| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mulscl | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  ( 𝐴  ·s  𝐵 )  ∈   No  ) | 
						
							| 2 | 1 | adantr | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  ( ( ∃ 𝑛  ∈  ℕs ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 )  ∧  𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ) )  ∧  ( ∃ 𝑚  ∈  ℕs ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) ) )  →  ( 𝐴  ·s  𝐵 )  ∈   No  ) | 
						
							| 3 |  | remulscllem2 | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  ( ( 𝑛  ∈  ℕs  ∧  𝑚  ∈  ℕs )  ∧  ( ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 )  ∧  ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 ) ) ) )  →  ∃ 𝑝  ∈  ℕs ( (  -us  ‘ 𝑝 )  <s  ( 𝐴  ·s  𝐵 )  ∧  ( 𝐴  ·s  𝐵 )  <s  𝑝 ) ) | 
						
							| 4 | 3 | expr | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  ( 𝑛  ∈  ℕs  ∧  𝑚  ∈  ℕs ) )  →  ( ( ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 )  ∧  ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 ) )  →  ∃ 𝑝  ∈  ℕs ( (  -us  ‘ 𝑝 )  <s  ( 𝐴  ·s  𝐵 )  ∧  ( 𝐴  ·s  𝐵 )  <s  𝑝 ) ) ) | 
						
							| 5 | 4 | rexlimdvva | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  ( ∃ 𝑛  ∈  ℕs ∃ 𝑚  ∈  ℕs ( ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 )  ∧  ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 ) )  →  ∃ 𝑝  ∈  ℕs ( (  -us  ‘ 𝑝 )  <s  ( 𝐴  ·s  𝐵 )  ∧  ( 𝐴  ·s  𝐵 )  <s  𝑝 ) ) ) | 
						
							| 6 |  | simpl | ⊢ ( ( ∃ 𝑛  ∈  ℕs ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 )  ∧  𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ) )  →  ∃ 𝑛  ∈  ℕs ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 ) ) | 
						
							| 7 |  | simpl | ⊢ ( ( ∃ 𝑚  ∈  ℕs ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) )  →  ∃ 𝑚  ∈  ℕs ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 ) ) | 
						
							| 8 | 6 7 | anim12i | ⊢ ( ( ( ∃ 𝑛  ∈  ℕs ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 )  ∧  𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ) )  ∧  ( ∃ 𝑚  ∈  ℕs ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) )  →  ( ∃ 𝑛  ∈  ℕs ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 )  ∧  ∃ 𝑚  ∈  ℕs ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 ) ) ) | 
						
							| 9 |  | reeanv | ⊢ ( ∃ 𝑛  ∈  ℕs ∃ 𝑚  ∈  ℕs ( ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 )  ∧  ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 ) )  ↔  ( ∃ 𝑛  ∈  ℕs ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 )  ∧  ∃ 𝑚  ∈  ℕs ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 ) ) ) | 
						
							| 10 | 8 9 | sylibr | ⊢ ( ( ( ∃ 𝑛  ∈  ℕs ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 )  ∧  𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ) )  ∧  ( ∃ 𝑚  ∈  ℕs ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) )  →  ∃ 𝑛  ∈  ℕs ∃ 𝑚  ∈  ℕs ( ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 )  ∧  ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 ) ) ) | 
						
							| 11 | 5 10 | impel | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  ( ( ∃ 𝑛  ∈  ℕs ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 )  ∧  𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ) )  ∧  ( ∃ 𝑚  ∈  ℕs ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) ) )  →  ∃ 𝑝  ∈  ℕs ( (  -us  ‘ 𝑝 )  <s  ( 𝐴  ·s  𝐵 )  ∧  ( 𝐴  ·s  𝐵 )  <s  𝑝 ) ) | 
						
							| 12 |  | simpr | ⊢ ( ( ∃ 𝑛  ∈  ℕs ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 )  ∧  𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ) )  →  𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ) ) | 
						
							| 13 |  | simpr | ⊢ ( ( ∃ 𝑚  ∈  ℕs ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) )  →  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) | 
						
							| 14 | 12 13 | anim12i | ⊢ ( ( ( ∃ 𝑛  ∈  ℕs ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 )  ∧  𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ) )  ∧  ( ∃ 𝑚  ∈  ℕs ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) )  →  ( 𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) ) | 
						
							| 15 |  | recut | ⊢ ( 𝐴  ∈   No   →  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  <<s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ) | 
						
							| 16 | 15 | adantr | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  <<s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ) | 
						
							| 17 | 16 | adantr | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  ( 𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) )  →  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  <<s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ) | 
						
							| 18 |  | recut | ⊢ ( 𝐵  ∈   No   →  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  <<s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) | 
						
							| 19 | 18 | ad2antlr | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  ( 𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) )  →  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  <<s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) | 
						
							| 20 |  | simprl | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  ( 𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) )  →  𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ) ) | 
						
							| 21 |  | simprr | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  ( 𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) )  →  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) | 
						
							| 22 | 17 19 20 21 | mulsunif2 | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  ( 𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) )  →  ( 𝐴  ·s  𝐵 )  =  ( ( { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) ) }  ∪  { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) } )  |s  ( { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) ) }  ∪  { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) } ) ) ) | 
						
							| 23 |  | r19.41v | ⊢ ( ∃ 𝑛  ∈  ℕs ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ( ∃ 𝑛  ∈  ℕs 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 24 | 23 | exbii | ⊢ ( ∃ 𝑡 ∃ 𝑛  ∈  ℕs ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑡 ( ∃ 𝑛  ∈  ℕs 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 25 |  | rexcom4 | ⊢ ( ∃ 𝑛  ∈  ℕs ∃ 𝑡 ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑡 ∃ 𝑛  ∈  ℕs ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 26 |  | eqeq1 | ⊢ ( 𝑥  =  𝑡  →  ( 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ↔  𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) ) ) | 
						
							| 27 | 26 | rexbidv | ⊢ ( 𝑥  =  𝑡  →  ( ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ↔  ∃ 𝑛  ∈  ℕs 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) ) ) | 
						
							| 28 | 27 | rexab | ⊢ ( ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) )  ↔  ∃ 𝑡 ( ∃ 𝑛  ∈  ℕs 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 29 | 24 25 28 | 3bitr4ri | ⊢ ( ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) )  ↔  ∃ 𝑛  ∈  ℕs ∃ 𝑡 ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 30 |  | ovex | ⊢ ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∈  V | 
						
							| 31 |  | oveq2 | ⊢ ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  →  ( 𝐴  -s  𝑡 )  =  ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) ) ) | 
						
							| 32 | 31 | oveq1d | ⊢ ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  →  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) )  =  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) ) | 
						
							| 33 | 32 | oveq2d | ⊢ ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  →  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) )  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) | 
						
							| 34 | 33 | eqeq2d | ⊢ ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  →  ( 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 35 | 34 | rexbidv | ⊢ ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  →  ( ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) )  ↔  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 36 | 30 35 | ceqsexv | ⊢ ( ∃ 𝑡 ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) | 
						
							| 37 |  | r19.41v | ⊢ ( ∃ 𝑚  ∈  ℕs ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ( ∃ 𝑚  ∈  ℕs 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 38 | 37 | exbii | ⊢ ( ∃ 𝑢 ∃ 𝑚  ∈  ℕs ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑢 ( ∃ 𝑚  ∈  ℕs 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 39 |  | rexcom4 | ⊢ ( ∃ 𝑚  ∈  ℕs ∃ 𝑢 ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑢 ∃ 𝑚  ∈  ℕs ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 40 |  | eqeq1 | ⊢ ( 𝑦  =  𝑢  →  ( 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ↔  𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) ) ) | 
						
							| 41 | 40 | rexbidv | ⊢ ( 𝑦  =  𝑢  →  ( ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ↔  ∃ 𝑚  ∈  ℕs 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) ) ) | 
						
							| 42 | 41 | rexab | ⊢ ( ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) )  ↔  ∃ 𝑢 ( ∃ 𝑚  ∈  ℕs 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 43 | 38 39 42 | 3bitr4ri | ⊢ ( ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) )  ↔  ∃ 𝑚  ∈  ℕs ∃ 𝑢 ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 44 | 36 43 | bitri | ⊢ ( ∃ 𝑡 ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑚  ∈  ℕs ∃ 𝑢 ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 45 |  | ovex | ⊢ ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∈  V | 
						
							| 46 |  | oveq2 | ⊢ ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  →  ( 𝐵  -s  𝑢 )  =  ( 𝐵  -s  ( 𝐵  -s  (  1s   /su  𝑚 ) ) ) ) | 
						
							| 47 | 46 | oveq2d | ⊢ ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  →  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) )  =  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  ( 𝐵  -s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 48 | 47 | oveq2d | ⊢ ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  →  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) )  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  ( 𝐵  -s  (  1s   /su  𝑚 ) ) ) ) ) ) | 
						
							| 49 | 48 | eqeq2d | ⊢ ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  →  ( 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  ( 𝐵  -s  (  1s   /su  𝑚 ) ) ) ) ) ) ) | 
						
							| 50 | 45 49 | ceqsexv | ⊢ ( ∃ 𝑢 ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  ( 𝐵  -s  (  1s   /su  𝑚 ) ) ) ) ) ) | 
						
							| 51 |  | simplll | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  𝐴  ∈   No  ) | 
						
							| 52 |  | 1sno | ⊢  1s   ∈   No | 
						
							| 53 | 52 | a1i | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →   1s   ∈   No  ) | 
						
							| 54 |  | nnsno | ⊢ ( 𝑛  ∈  ℕs  →  𝑛  ∈   No  ) | 
						
							| 55 | 54 | ad2antlr | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  𝑛  ∈   No  ) | 
						
							| 56 |  | nnne0s | ⊢ ( 𝑛  ∈  ℕs  →  𝑛  ≠   0s  ) | 
						
							| 57 | 56 | ad2antlr | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  𝑛  ≠   0s  ) | 
						
							| 58 | 53 55 57 | divscld | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  (  1s   /su  𝑛 )  ∈   No  ) | 
						
							| 59 | 51 58 | nncansd | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  =  (  1s   /su  𝑛 ) ) | 
						
							| 60 |  | simpllr | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  𝐵  ∈   No  ) | 
						
							| 61 |  | nnsno | ⊢ ( 𝑚  ∈  ℕs  →  𝑚  ∈   No  ) | 
						
							| 62 | 61 | adantl | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  𝑚  ∈   No  ) | 
						
							| 63 |  | nnne0s | ⊢ ( 𝑚  ∈  ℕs  →  𝑚  ≠   0s  ) | 
						
							| 64 | 63 | adantl | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  𝑚  ≠   0s  ) | 
						
							| 65 | 53 62 64 | divscld | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  (  1s   /su  𝑚 )  ∈   No  ) | 
						
							| 66 | 60 65 | nncansd | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( 𝐵  -s  ( 𝐵  -s  (  1s   /su  𝑚 ) ) )  =  (  1s   /su  𝑚 ) ) | 
						
							| 67 | 59 66 | oveq12d | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  ( 𝐵  -s  (  1s   /su  𝑚 ) ) ) )  =  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) | 
						
							| 68 | 67 | oveq2d | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  ( 𝐵  -s  (  1s   /su  𝑚 ) ) ) ) )  =  ( ( 𝐴  ·s  𝐵 )  -s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) | 
						
							| 69 | 68 | eqeq2d | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  ( 𝐵  -s  (  1s   /su  𝑚 ) ) ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 70 | 50 69 | bitrid | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( ∃ 𝑢 ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 71 | 70 | rexbidva | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  →  ( ∃ 𝑚  ∈  ℕs ∃ 𝑢 ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑚  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 72 | 44 71 | bitrid | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  →  ( ∃ 𝑡 ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑚  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 73 | 72 | rexbidva | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  ( ∃ 𝑛  ∈  ℕs ∃ 𝑡 ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑛  ∈  ℕs ∃ 𝑚  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 74 |  | remulscllem1 | ⊢ ( ∃ 𝑛  ∈  ℕs ∃ 𝑚  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) )  ↔  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) ) | 
						
							| 75 | 73 74 | bitrdi | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  ( ∃ 𝑛  ∈  ℕs ∃ 𝑡 ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) ) ) | 
						
							| 76 | 29 75 | bitrid | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  ( ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) )  ↔  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) ) ) | 
						
							| 77 | 76 | abbidv | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) ) }  =  { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) } ) | 
						
							| 78 |  | r19.41v | ⊢ ( ∃ 𝑛  ∈  ℕs ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ( ∃ 𝑛  ∈  ℕs 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 79 | 78 | exbii | ⊢ ( ∃ 𝑡 ∃ 𝑛  ∈  ℕs ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑡 ( ∃ 𝑛  ∈  ℕs 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 80 |  | rexcom4 | ⊢ ( ∃ 𝑛  ∈  ℕs ∃ 𝑡 ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑡 ∃ 𝑛  ∈  ℕs ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 81 |  | eqeq1 | ⊢ ( 𝑥  =  𝑡  →  ( 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ↔  𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) ) ) | 
						
							| 82 | 81 | rexbidv | ⊢ ( 𝑥  =  𝑡  →  ( ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ↔  ∃ 𝑛  ∈  ℕs 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) ) ) | 
						
							| 83 | 82 | rexab | ⊢ ( ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) )  ↔  ∃ 𝑡 ( ∃ 𝑛  ∈  ℕs 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 84 | 79 80 83 | 3bitr4ri | ⊢ ( ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) )  ↔  ∃ 𝑛  ∈  ℕs ∃ 𝑡 ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 85 |  | ovex | ⊢ ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∈  V | 
						
							| 86 |  | oveq1 | ⊢ ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  →  ( 𝑡  -s  𝐴 )  =  ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 ) ) | 
						
							| 87 | 86 | oveq1d | ⊢ ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  →  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) )  =  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) | 
						
							| 88 | 87 | oveq2d | ⊢ ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  →  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) )  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) | 
						
							| 89 | 88 | eqeq2d | ⊢ ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  →  ( 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 90 | 89 | rexbidv | ⊢ ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  →  ( ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) )  ↔  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 91 | 85 90 | ceqsexv | ⊢ ( ∃ 𝑡 ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) | 
						
							| 92 |  | r19.41v | ⊢ ( ∃ 𝑚  ∈  ℕs ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ( ∃ 𝑚  ∈  ℕs 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 93 | 92 | exbii | ⊢ ( ∃ 𝑢 ∃ 𝑚  ∈  ℕs ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑢 ( ∃ 𝑚  ∈  ℕs 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 94 |  | rexcom4 | ⊢ ( ∃ 𝑚  ∈  ℕs ∃ 𝑢 ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑢 ∃ 𝑚  ∈  ℕs ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 95 |  | eqeq1 | ⊢ ( 𝑦  =  𝑢  →  ( 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ↔  𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) ) ) | 
						
							| 96 | 95 | rexbidv | ⊢ ( 𝑦  =  𝑢  →  ( ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ↔  ∃ 𝑚  ∈  ℕs 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) ) ) | 
						
							| 97 | 96 | rexab | ⊢ ( ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) )  ↔  ∃ 𝑢 ( ∃ 𝑚  ∈  ℕs 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 98 | 93 94 97 | 3bitr4ri | ⊢ ( ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) )  ↔  ∃ 𝑚  ∈  ℕs ∃ 𝑢 ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 99 | 91 98 | bitri | ⊢ ( ∃ 𝑡 ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑚  ∈  ℕs ∃ 𝑢 ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 100 |  | ovex | ⊢ ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∈  V | 
						
							| 101 |  | oveq1 | ⊢ ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  →  ( 𝑢  -s  𝐵 )  =  ( ( 𝐵  +s  (  1s   /su  𝑚 ) )  -s  𝐵 ) ) | 
						
							| 102 | 101 | oveq2d | ⊢ ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  →  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) )  =  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( ( 𝐵  +s  (  1s   /su  𝑚 ) )  -s  𝐵 ) ) ) | 
						
							| 103 | 102 | oveq2d | ⊢ ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  →  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) )  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( ( 𝐵  +s  (  1s   /su  𝑚 ) )  -s  𝐵 ) ) ) ) | 
						
							| 104 | 103 | eqeq2d | ⊢ ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  →  ( 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( ( 𝐵  +s  (  1s   /su  𝑚 ) )  -s  𝐵 ) ) ) ) ) | 
						
							| 105 | 100 104 | ceqsexv | ⊢ ( ∃ 𝑢 ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( ( 𝐵  +s  (  1s   /su  𝑚 ) )  -s  𝐵 ) ) ) ) | 
						
							| 106 |  | pncan2s | ⊢ ( ( 𝐴  ∈   No   ∧  (  1s   /su  𝑛 )  ∈   No  )  →  ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  =  (  1s   /su  𝑛 ) ) | 
						
							| 107 | 51 58 106 | syl2anc | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  =  (  1s   /su  𝑛 ) ) | 
						
							| 108 |  | pncan2s | ⊢ ( ( 𝐵  ∈   No   ∧  (  1s   /su  𝑚 )  ∈   No  )  →  ( ( 𝐵  +s  (  1s   /su  𝑚 ) )  -s  𝐵 )  =  (  1s   /su  𝑚 ) ) | 
						
							| 109 | 60 65 108 | syl2anc | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( ( 𝐵  +s  (  1s   /su  𝑚 ) )  -s  𝐵 )  =  (  1s   /su  𝑚 ) ) | 
						
							| 110 | 107 109 | oveq12d | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( ( 𝐵  +s  (  1s   /su  𝑚 ) )  -s  𝐵 ) )  =  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) | 
						
							| 111 | 110 | oveq2d | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( ( 𝐵  +s  (  1s   /su  𝑚 ) )  -s  𝐵 ) ) )  =  ( ( 𝐴  ·s  𝐵 )  -s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) | 
						
							| 112 | 111 | eqeq2d | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( ( 𝐵  +s  (  1s   /su  𝑚 ) )  -s  𝐵 ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 113 | 105 112 | bitrid | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( ∃ 𝑢 ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 114 | 113 | rexbidva | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  →  ( ∃ 𝑚  ∈  ℕs ∃ 𝑢 ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑚  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 115 | 99 114 | bitrid | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  →  ( ∃ 𝑡 ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑚  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 116 | 115 | rexbidva | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  ( ∃ 𝑛  ∈  ℕs ∃ 𝑡 ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑛  ∈  ℕs ∃ 𝑚  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 117 | 116 74 | bitrdi | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  ( ∃ 𝑛  ∈  ℕs ∃ 𝑡 ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) ) ) | 
						
							| 118 | 84 117 | bitrid | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  ( ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) )  ↔  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) ) ) | 
						
							| 119 | 118 | abbidv | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) }  =  { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) } ) | 
						
							| 120 | 77 119 | uneq12d | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  ( { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) ) }  ∪  { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) } )  =  ( { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) }  ∪  { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) } ) ) | 
						
							| 121 |  | unidm | ⊢ ( { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) }  ∪  { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) } )  =  { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) } | 
						
							| 122 | 120 121 | eqtrdi | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  ( { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) ) }  ∪  { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) } )  =  { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) } ) | 
						
							| 123 |  | r19.41v | ⊢ ( ∃ 𝑛  ∈  ℕs ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ( ∃ 𝑛  ∈  ℕs 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 124 | 123 | exbii | ⊢ ( ∃ 𝑡 ∃ 𝑛  ∈  ℕs ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑡 ( ∃ 𝑛  ∈  ℕs 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 125 |  | rexcom4 | ⊢ ( ∃ 𝑛  ∈  ℕs ∃ 𝑡 ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑡 ∃ 𝑛  ∈  ℕs ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 126 | 27 | rexab | ⊢ ( ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) )  ↔  ∃ 𝑡 ( ∃ 𝑛  ∈  ℕs 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 127 | 124 125 126 | 3bitr4ri | ⊢ ( ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) )  ↔  ∃ 𝑛  ∈  ℕs ∃ 𝑡 ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 128 | 31 | oveq1d | ⊢ ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  →  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) )  =  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) ) | 
						
							| 129 | 128 | oveq2d | ⊢ ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  →  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) )  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) | 
						
							| 130 | 129 | eqeq2d | ⊢ ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  →  ( 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 131 | 130 | rexbidv | ⊢ ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  →  ( ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) )  ↔  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 132 | 30 131 | ceqsexv | ⊢ ( ∃ 𝑡 ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) | 
						
							| 133 |  | r19.41v | ⊢ ( ∃ 𝑚  ∈  ℕs ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ( ∃ 𝑚  ∈  ℕs 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 134 | 133 | exbii | ⊢ ( ∃ 𝑢 ∃ 𝑚  ∈  ℕs ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑢 ( ∃ 𝑚  ∈  ℕs 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 135 |  | rexcom4 | ⊢ ( ∃ 𝑚  ∈  ℕs ∃ 𝑢 ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑢 ∃ 𝑚  ∈  ℕs ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 136 | 96 | rexab | ⊢ ( ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) )  ↔  ∃ 𝑢 ( ∃ 𝑚  ∈  ℕs 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 137 | 134 135 136 | 3bitr4ri | ⊢ ( ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) )  ↔  ∃ 𝑚  ∈  ℕs ∃ 𝑢 ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 138 | 132 137 | bitri | ⊢ ( ∃ 𝑡 ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑚  ∈  ℕs ∃ 𝑢 ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) ) ) ) | 
						
							| 139 | 101 | oveq2d | ⊢ ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  →  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) )  =  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( ( 𝐵  +s  (  1s   /su  𝑚 ) )  -s  𝐵 ) ) ) | 
						
							| 140 | 139 | oveq2d | ⊢ ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  →  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) )  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( ( 𝐵  +s  (  1s   /su  𝑚 ) )  -s  𝐵 ) ) ) ) | 
						
							| 141 | 140 | eqeq2d | ⊢ ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  →  ( 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( ( 𝐵  +s  (  1s   /su  𝑚 ) )  -s  𝐵 ) ) ) ) ) | 
						
							| 142 | 100 141 | ceqsexv | ⊢ ( ∃ 𝑢 ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( ( 𝐵  +s  (  1s   /su  𝑚 ) )  -s  𝐵 ) ) ) ) | 
						
							| 143 | 59 109 | oveq12d | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( ( 𝐵  +s  (  1s   /su  𝑚 ) )  -s  𝐵 ) )  =  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) | 
						
							| 144 | 143 | oveq2d | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( ( 𝐵  +s  (  1s   /su  𝑚 ) )  -s  𝐵 ) ) )  =  ( ( 𝐴  ·s  𝐵 )  +s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) | 
						
							| 145 | 144 | eqeq2d | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( ( 𝐵  +s  (  1s   /su  𝑚 ) )  -s  𝐵 ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 146 | 142 145 | bitrid | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( ∃ 𝑢 ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 147 | 146 | rexbidva | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  →  ( ∃ 𝑚  ∈  ℕs ∃ 𝑢 ( 𝑢  =  ( 𝐵  +s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  ( 𝐴  -s  (  1s   /su  𝑛 ) ) )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑚  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 148 | 138 147 | bitrid | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  →  ( ∃ 𝑡 ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑚  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 149 | 148 | rexbidva | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  ( ∃ 𝑛  ∈  ℕs ∃ 𝑡 ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑛  ∈  ℕs ∃ 𝑚  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 150 |  | remulscllem1 | ⊢ ( ∃ 𝑛  ∈  ℕs ∃ 𝑚  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) )  ↔  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) ) | 
						
							| 151 | 149 150 | bitrdi | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  ( ∃ 𝑛  ∈  ℕs ∃ 𝑡 ( 𝑡  =  ( 𝐴  -s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) ) )  ↔  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) ) ) | 
						
							| 152 | 127 151 | bitrid | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  ( ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) )  ↔  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) ) ) | 
						
							| 153 | 152 | abbidv | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) ) }  =  { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) } ) | 
						
							| 154 |  | r19.41v | ⊢ ( ∃ 𝑛  ∈  ℕs ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ( ∃ 𝑛  ∈  ℕs 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 155 | 154 | exbii | ⊢ ( ∃ 𝑡 ∃ 𝑛  ∈  ℕs ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑡 ( ∃ 𝑛  ∈  ℕs 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 156 |  | rexcom4 | ⊢ ( ∃ 𝑛  ∈  ℕs ∃ 𝑡 ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑡 ∃ 𝑛  ∈  ℕs ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 157 | 82 | rexab | ⊢ ( ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) )  ↔  ∃ 𝑡 ( ∃ 𝑛  ∈  ℕs 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 158 | 155 156 157 | 3bitr4ri | ⊢ ( ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) )  ↔  ∃ 𝑛  ∈  ℕs ∃ 𝑡 ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 159 | 86 | oveq1d | ⊢ ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  →  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) )  =  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) | 
						
							| 160 | 159 | oveq2d | ⊢ ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  →  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) )  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) | 
						
							| 161 | 160 | eqeq2d | ⊢ ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  →  ( 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 162 | 161 | rexbidv | ⊢ ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  →  ( ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) )  ↔  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 163 | 85 162 | ceqsexv | ⊢ ( ∃ 𝑡 ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) | 
						
							| 164 |  | r19.41v | ⊢ ( ∃ 𝑚  ∈  ℕs ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ( ∃ 𝑚  ∈  ℕs 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 165 | 164 | exbii | ⊢ ( ∃ 𝑢 ∃ 𝑚  ∈  ℕs ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑢 ( ∃ 𝑚  ∈  ℕs 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 166 |  | rexcom4 | ⊢ ( ∃ 𝑚  ∈  ℕs ∃ 𝑢 ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑢 ∃ 𝑚  ∈  ℕs ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 167 | 41 | rexab | ⊢ ( ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) )  ↔  ∃ 𝑢 ( ∃ 𝑚  ∈  ℕs 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 168 | 165 166 167 | 3bitr4ri | ⊢ ( ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) )  ↔  ∃ 𝑚  ∈  ℕs ∃ 𝑢 ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 169 | 163 168 | bitri | ⊢ ( ∃ 𝑡 ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑚  ∈  ℕs ∃ 𝑢 ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) ) ) | 
						
							| 170 | 46 | oveq2d | ⊢ ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  →  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) )  =  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  ( 𝐵  -s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 171 | 170 | oveq2d | ⊢ ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  →  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) )  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  ( 𝐵  -s  (  1s   /su  𝑚 ) ) ) ) ) ) | 
						
							| 172 | 171 | eqeq2d | ⊢ ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  →  ( 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  ( 𝐵  -s  (  1s   /su  𝑚 ) ) ) ) ) ) ) | 
						
							| 173 | 45 172 | ceqsexv | ⊢ ( ∃ 𝑢 ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  ( 𝐵  -s  (  1s   /su  𝑚 ) ) ) ) ) ) | 
						
							| 174 | 107 66 | oveq12d | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  ( 𝐵  -s  (  1s   /su  𝑚 ) ) ) )  =  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) | 
						
							| 175 | 174 | oveq2d | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  ( 𝐵  -s  (  1s   /su  𝑚 ) ) ) ) )  =  ( ( 𝐴  ·s  𝐵 )  +s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) | 
						
							| 176 | 175 | eqeq2d | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  ( 𝐵  -s  (  1s   /su  𝑚 ) ) ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 177 | 173 176 | bitrid | ⊢ ( ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  ∧  𝑚  ∈  ℕs )  →  ( ∃ 𝑢 ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 178 | 177 | rexbidva | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  →  ( ∃ 𝑚  ∈  ℕs ∃ 𝑢 ( 𝑢  =  ( 𝐵  -s  (  1s   /su  𝑚 ) )  ∧  𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( ( 𝐴  +s  (  1s   /su  𝑛 ) )  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑚  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 179 | 169 178 | bitrid | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  𝑛  ∈  ℕs )  →  ( ∃ 𝑡 ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑚  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 180 | 179 | rexbidva | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  ( ∃ 𝑛  ∈  ℕs ∃ 𝑡 ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑛  ∈  ℕs ∃ 𝑚  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( (  1s   /su  𝑛 )  ·s  (  1s   /su  𝑚 ) ) ) ) ) | 
						
							| 181 | 180 150 | bitrdi | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  ( ∃ 𝑛  ∈  ℕs ∃ 𝑡 ( 𝑡  =  ( 𝐴  +s  (  1s   /su  𝑛 ) )  ∧  ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) )  ↔  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) ) ) | 
						
							| 182 | 158 181 | bitrid | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  ( ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) )  ↔  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) ) ) | 
						
							| 183 | 182 | abbidv | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) }  =  { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) } ) | 
						
							| 184 | 153 183 | uneq12d | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  ( { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) ) }  ∪  { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) } )  =  ( { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) }  ∪  { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) } ) ) | 
						
							| 185 |  | unidm | ⊢ ( { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) }  ∪  { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) } )  =  { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) } | 
						
							| 186 | 184 185 | eqtrdi | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  ( { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) ) }  ∪  { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) } )  =  { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) } ) | 
						
							| 187 | 122 186 | oveq12d | ⊢ ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  →  ( ( { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) ) }  ∪  { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) } )  |s  ( { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) ) }  ∪  { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) } ) )  =  ( { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) }  |s  { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) } ) ) | 
						
							| 188 | 187 | adantr | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  ( 𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) )  →  ( ( { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝐵  -s  𝑢 ) ) ) }  ∪  { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝑢  -s  𝐵 ) ) ) } )  |s  ( { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝐴  -s  𝑡 )  ·s  ( 𝑢  -s  𝐵 ) ) ) }  ∪  { 𝑧  ∣  ∃ 𝑡  ∈  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ∃ 𝑢  ∈  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) } 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  ( ( 𝑡  -s  𝐴 )  ·s  ( 𝐵  -s  𝑢 ) ) ) } ) )  =  ( { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) }  |s  { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) } ) ) | 
						
							| 189 | 22 188 | eqtrd | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  ( 𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) )  →  ( 𝐴  ·s  𝐵 )  =  ( { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) }  |s  { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) } ) ) | 
						
							| 190 | 14 189 | sylan2 | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  ( ( ∃ 𝑛  ∈  ℕs ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 )  ∧  𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ) )  ∧  ( ∃ 𝑚  ∈  ℕs ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) ) )  →  ( 𝐴  ·s  𝐵 )  =  ( { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) }  |s  { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) } ) ) | 
						
							| 191 | 2 11 190 | jca32 | ⊢ ( ( ( 𝐴  ∈   No   ∧  𝐵  ∈   No  )  ∧  ( ( ∃ 𝑛  ∈  ℕs ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 )  ∧  𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ) )  ∧  ( ∃ 𝑚  ∈  ℕs ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) ) )  →  ( ( 𝐴  ·s  𝐵 )  ∈   No   ∧  ( ∃ 𝑝  ∈  ℕs ( (  -us  ‘ 𝑝 )  <s  ( 𝐴  ·s  𝐵 )  ∧  ( 𝐴  ·s  𝐵 )  <s  𝑝 )  ∧  ( 𝐴  ·s  𝐵 )  =  ( { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) }  |s  { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) } ) ) ) ) | 
						
							| 192 | 191 | an4s | ⊢ ( ( ( 𝐴  ∈   No   ∧  ( ∃ 𝑛  ∈  ℕs ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 )  ∧  𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ) ) )  ∧  ( 𝐵  ∈   No   ∧  ( ∃ 𝑚  ∈  ℕs ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) ) )  →  ( ( 𝐴  ·s  𝐵 )  ∈   No   ∧  ( ∃ 𝑝  ∈  ℕs ( (  -us  ‘ 𝑝 )  <s  ( 𝐴  ·s  𝐵 )  ∧  ( 𝐴  ·s  𝐵 )  <s  𝑝 )  ∧  ( 𝐴  ·s  𝐵 )  =  ( { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) }  |s  { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) } ) ) ) ) | 
						
							| 193 |  | elreno | ⊢ ( 𝐴  ∈  ℝs  ↔  ( 𝐴  ∈   No   ∧  ( ∃ 𝑛  ∈  ℕs ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 )  ∧  𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ) ) ) ) | 
						
							| 194 |  | elreno | ⊢ ( 𝐵  ∈  ℝs  ↔  ( 𝐵  ∈   No   ∧  ( ∃ 𝑚  ∈  ℕs ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) ) ) | 
						
							| 195 | 193 194 | anbi12i | ⊢ ( ( 𝐴  ∈  ℝs  ∧  𝐵  ∈  ℝs )  ↔  ( ( 𝐴  ∈   No   ∧  ( ∃ 𝑛  ∈  ℕs ( (  -us  ‘ 𝑛 )  <s  𝐴  ∧  𝐴  <s  𝑛 )  ∧  𝐴  =  ( { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  -s  (  1s   /su  𝑛 ) ) }  |s  { 𝑥  ∣  ∃ 𝑛  ∈  ℕs 𝑥  =  ( 𝐴  +s  (  1s   /su  𝑛 ) ) } ) ) )  ∧  ( 𝐵  ∈   No   ∧  ( ∃ 𝑚  ∈  ℕs ( (  -us  ‘ 𝑚 )  <s  𝐵  ∧  𝐵  <s  𝑚 )  ∧  𝐵  =  ( { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  -s  (  1s   /su  𝑚 ) ) }  |s  { 𝑦  ∣  ∃ 𝑚  ∈  ℕs 𝑦  =  ( 𝐵  +s  (  1s   /su  𝑚 ) ) } ) ) ) ) ) | 
						
							| 196 |  | elreno | ⊢ ( ( 𝐴  ·s  𝐵 )  ∈  ℝs  ↔  ( ( 𝐴  ·s  𝐵 )  ∈   No   ∧  ( ∃ 𝑝  ∈  ℕs ( (  -us  ‘ 𝑝 )  <s  ( 𝐴  ·s  𝐵 )  ∧  ( 𝐴  ·s  𝐵 )  <s  𝑝 )  ∧  ( 𝐴  ·s  𝐵 )  =  ( { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  -s  (  1s   /su  𝑝 ) ) }  |s  { 𝑧  ∣  ∃ 𝑝  ∈  ℕs 𝑧  =  ( ( 𝐴  ·s  𝐵 )  +s  (  1s   /su  𝑝 ) ) } ) ) ) ) | 
						
							| 197 | 192 195 196 | 3imtr4i | ⊢ ( ( 𝐴  ∈  ℝs  ∧  𝐵  ∈  ℝs )  →  ( 𝐴  ·s  𝐵 )  ∈  ℝs ) |