| Step | Hyp | Ref | Expression | 
						
							| 1 |  | eropr.1 | ⊢ 𝐽  =  ( 𝐴  /  𝑅 ) | 
						
							| 2 |  | eropr.2 | ⊢ 𝐾  =  ( 𝐵  /  𝑆 ) | 
						
							| 3 |  | eropr.3 | ⊢ ( 𝜑  →  𝑇  ∈  𝑍 ) | 
						
							| 4 |  | eropr.4 | ⊢ ( 𝜑  →  𝑅  Er  𝑈 ) | 
						
							| 5 |  | eropr.5 | ⊢ ( 𝜑  →  𝑆  Er  𝑉 ) | 
						
							| 6 |  | eropr.6 | ⊢ ( 𝜑  →  𝑇  Er  𝑊 ) | 
						
							| 7 |  | eropr.7 | ⊢ ( 𝜑  →  𝐴  ⊆  𝑈 ) | 
						
							| 8 |  | eropr.8 | ⊢ ( 𝜑  →  𝐵  ⊆  𝑉 ) | 
						
							| 9 |  | eropr.9 | ⊢ ( 𝜑  →  𝐶  ⊆  𝑊 ) | 
						
							| 10 |  | eropr.10 | ⊢ ( 𝜑  →   +  : ( 𝐴  ×  𝐵 ) ⟶ 𝐶 ) | 
						
							| 11 |  | eropr.11 | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  ( ( 𝑟 𝑅 𝑠  ∧  𝑡 𝑆 𝑢 )  →  ( 𝑟  +  𝑡 ) 𝑇 ( 𝑠  +  𝑢 ) ) ) | 
						
							| 12 |  | elqsi | ⊢ ( 𝑋  ∈  ( 𝐴  /  𝑅 )  →  ∃ 𝑝  ∈  𝐴 𝑋  =  [ 𝑝 ] 𝑅 ) | 
						
							| 13 | 12 1 | eleq2s | ⊢ ( 𝑋  ∈  𝐽  →  ∃ 𝑝  ∈  𝐴 𝑋  =  [ 𝑝 ] 𝑅 ) | 
						
							| 14 |  | elqsi | ⊢ ( 𝑌  ∈  ( 𝐵  /  𝑆 )  →  ∃ 𝑞  ∈  𝐵 𝑌  =  [ 𝑞 ] 𝑆 ) | 
						
							| 15 | 14 2 | eleq2s | ⊢ ( 𝑌  ∈  𝐾  →  ∃ 𝑞  ∈  𝐵 𝑌  =  [ 𝑞 ] 𝑆 ) | 
						
							| 16 | 13 15 | anim12i | ⊢ ( ( 𝑋  ∈  𝐽  ∧  𝑌  ∈  𝐾 )  →  ( ∃ 𝑝  ∈  𝐴 𝑋  =  [ 𝑝 ] 𝑅  ∧  ∃ 𝑞  ∈  𝐵 𝑌  =  [ 𝑞 ] 𝑆 ) ) | 
						
							| 17 | 16 | adantl | ⊢ ( ( 𝜑  ∧  ( 𝑋  ∈  𝐽  ∧  𝑌  ∈  𝐾 ) )  →  ( ∃ 𝑝  ∈  𝐴 𝑋  =  [ 𝑝 ] 𝑅  ∧  ∃ 𝑞  ∈  𝐵 𝑌  =  [ 𝑞 ] 𝑆 ) ) | 
						
							| 18 |  | reeanv | ⊢ ( ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ↔  ( ∃ 𝑝  ∈  𝐴 𝑋  =  [ 𝑝 ] 𝑅  ∧  ∃ 𝑞  ∈  𝐵 𝑌  =  [ 𝑞 ] 𝑆 ) ) | 
						
							| 19 | 17 18 | sylibr | ⊢ ( ( 𝜑  ∧  ( 𝑋  ∈  𝐽  ∧  𝑌  ∈  𝐾 ) )  →  ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 ) ) | 
						
							| 20 | 3 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑋  ∈  𝐽  ∧  𝑌  ∈  𝐾 ) )  →  𝑇  ∈  𝑍 ) | 
						
							| 21 |  | ecexg | ⊢ ( 𝑇  ∈  𝑍  →  [ ( 𝑝  +  𝑞 ) ] 𝑇  ∈  V ) | 
						
							| 22 |  | elisset | ⊢ ( [ ( 𝑝  +  𝑞 ) ] 𝑇  ∈  V  →  ∃ 𝑧 𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) | 
						
							| 23 | 20 21 22 | 3syl | ⊢ ( ( 𝜑  ∧  ( 𝑋  ∈  𝐽  ∧  𝑌  ∈  𝐾 ) )  →  ∃ 𝑧 𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) | 
						
							| 24 | 23 | biantrud | ⊢ ( ( 𝜑  ∧  ( 𝑋  ∈  𝐽  ∧  𝑌  ∈  𝐾 ) )  →  ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ↔  ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  ∃ 𝑧 𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) ) ) | 
						
							| 25 | 24 | 2rexbidv | ⊢ ( ( 𝜑  ∧  ( 𝑋  ∈  𝐽  ∧  𝑌  ∈  𝐾 ) )  →  ( ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ↔  ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  ∃ 𝑧 𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) ) ) | 
						
							| 26 | 19 25 | mpbid | ⊢ ( ( 𝜑  ∧  ( 𝑋  ∈  𝐽  ∧  𝑌  ∈  𝐾 ) )  →  ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  ∃ 𝑧 𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) ) | 
						
							| 27 |  | 19.42v | ⊢ ( ∃ 𝑧 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ↔  ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  ∃ 𝑧 𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) ) | 
						
							| 28 | 27 | bicomi | ⊢ ( ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  ∃ 𝑧 𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ↔  ∃ 𝑧 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) ) | 
						
							| 29 | 28 | rexbii | ⊢ ( ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  ∃ 𝑧 𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ↔  ∃ 𝑞  ∈  𝐵 ∃ 𝑧 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) ) | 
						
							| 30 |  | rexcom4 | ⊢ ( ∃ 𝑞  ∈  𝐵 ∃ 𝑧 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ↔  ∃ 𝑧 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) ) | 
						
							| 31 | 29 30 | bitri | ⊢ ( ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  ∃ 𝑧 𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ↔  ∃ 𝑧 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) ) | 
						
							| 32 | 31 | rexbii | ⊢ ( ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  ∃ 𝑧 𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ↔  ∃ 𝑝  ∈  𝐴 ∃ 𝑧 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) ) | 
						
							| 33 |  | rexcom4 | ⊢ ( ∃ 𝑝  ∈  𝐴 ∃ 𝑧 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ↔  ∃ 𝑧 ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) ) | 
						
							| 34 | 32 33 | bitri | ⊢ ( ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  ∃ 𝑧 𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ↔  ∃ 𝑧 ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) ) | 
						
							| 35 | 26 34 | sylib | ⊢ ( ( 𝜑  ∧  ( 𝑋  ∈  𝐽  ∧  𝑌  ∈  𝐾 ) )  →  ∃ 𝑧 ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) ) | 
						
							| 36 |  | reeanv | ⊢ ( ∃ 𝑟  ∈  𝐴 ∃ 𝑠  ∈  𝐴 ( ∃ 𝑡  ∈  𝐵 ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑟  +  𝑡 ) ] 𝑇 )  ∧  ∃ 𝑢  ∈  𝐵 ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) )  ↔  ( ∃ 𝑟  ∈  𝐴 ∃ 𝑡  ∈  𝐵 ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑟  +  𝑡 ) ] 𝑇 )  ∧  ∃ 𝑠  ∈  𝐴 ∃ 𝑢  ∈  𝐵 ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) ) ) | 
						
							| 37 |  | eceq1 | ⊢ ( 𝑝  =  𝑟  →  [ 𝑝 ] 𝑅  =  [ 𝑟 ] 𝑅 ) | 
						
							| 38 | 37 | eqeq2d | ⊢ ( 𝑝  =  𝑟  →  ( 𝑋  =  [ 𝑝 ] 𝑅  ↔  𝑋  =  [ 𝑟 ] 𝑅 ) ) | 
						
							| 39 | 38 | anbi1d | ⊢ ( 𝑝  =  𝑟  →  ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ↔  ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 ) ) ) | 
						
							| 40 |  | oveq1 | ⊢ ( 𝑝  =  𝑟  →  ( 𝑝  +  𝑞 )  =  ( 𝑟  +  𝑞 ) ) | 
						
							| 41 | 40 | eceq1d | ⊢ ( 𝑝  =  𝑟  →  [ ( 𝑝  +  𝑞 ) ] 𝑇  =  [ ( 𝑟  +  𝑞 ) ] 𝑇 ) | 
						
							| 42 | 41 | eqeq2d | ⊢ ( 𝑝  =  𝑟  →  ( 𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇  ↔  𝑧  =  [ ( 𝑟  +  𝑞 ) ] 𝑇 ) ) | 
						
							| 43 | 39 42 | anbi12d | ⊢ ( 𝑝  =  𝑟  →  ( ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ↔  ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑟  +  𝑞 ) ] 𝑇 ) ) ) | 
						
							| 44 |  | eceq1 | ⊢ ( 𝑞  =  𝑡  →  [ 𝑞 ] 𝑆  =  [ 𝑡 ] 𝑆 ) | 
						
							| 45 | 44 | eqeq2d | ⊢ ( 𝑞  =  𝑡  →  ( 𝑌  =  [ 𝑞 ] 𝑆  ↔  𝑌  =  [ 𝑡 ] 𝑆 ) ) | 
						
							| 46 | 45 | anbi2d | ⊢ ( 𝑞  =  𝑡  →  ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ↔  ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 ) ) ) | 
						
							| 47 |  | oveq2 | ⊢ ( 𝑞  =  𝑡  →  ( 𝑟  +  𝑞 )  =  ( 𝑟  +  𝑡 ) ) | 
						
							| 48 | 47 | eceq1d | ⊢ ( 𝑞  =  𝑡  →  [ ( 𝑟  +  𝑞 ) ] 𝑇  =  [ ( 𝑟  +  𝑡 ) ] 𝑇 ) | 
						
							| 49 | 48 | eqeq2d | ⊢ ( 𝑞  =  𝑡  →  ( 𝑧  =  [ ( 𝑟  +  𝑞 ) ] 𝑇  ↔  𝑧  =  [ ( 𝑟  +  𝑡 ) ] 𝑇 ) ) | 
						
							| 50 | 46 49 | anbi12d | ⊢ ( 𝑞  =  𝑡  →  ( ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑟  +  𝑞 ) ] 𝑇 )  ↔  ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑟  +  𝑡 ) ] 𝑇 ) ) ) | 
						
							| 51 | 43 50 | cbvrex2vw | ⊢ ( ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ↔  ∃ 𝑟  ∈  𝐴 ∃ 𝑡  ∈  𝐵 ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑟  +  𝑡 ) ] 𝑇 ) ) | 
						
							| 52 |  | eceq1 | ⊢ ( 𝑝  =  𝑠  →  [ 𝑝 ] 𝑅  =  [ 𝑠 ] 𝑅 ) | 
						
							| 53 | 52 | eqeq2d | ⊢ ( 𝑝  =  𝑠  →  ( 𝑋  =  [ 𝑝 ] 𝑅  ↔  𝑋  =  [ 𝑠 ] 𝑅 ) ) | 
						
							| 54 | 53 | anbi1d | ⊢ ( 𝑝  =  𝑠  →  ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ↔  ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 ) ) ) | 
						
							| 55 |  | oveq1 | ⊢ ( 𝑝  =  𝑠  →  ( 𝑝  +  𝑞 )  =  ( 𝑠  +  𝑞 ) ) | 
						
							| 56 | 55 | eceq1d | ⊢ ( 𝑝  =  𝑠  →  [ ( 𝑝  +  𝑞 ) ] 𝑇  =  [ ( 𝑠  +  𝑞 ) ] 𝑇 ) | 
						
							| 57 | 56 | eqeq2d | ⊢ ( 𝑝  =  𝑠  →  ( 𝑤  =  [ ( 𝑝  +  𝑞 ) ] 𝑇  ↔  𝑤  =  [ ( 𝑠  +  𝑞 ) ] 𝑇 ) ) | 
						
							| 58 | 54 57 | anbi12d | ⊢ ( 𝑝  =  𝑠  →  ( ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ↔  ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑞 ) ] 𝑇 ) ) ) | 
						
							| 59 |  | eceq1 | ⊢ ( 𝑞  =  𝑢  →  [ 𝑞 ] 𝑆  =  [ 𝑢 ] 𝑆 ) | 
						
							| 60 | 59 | eqeq2d | ⊢ ( 𝑞  =  𝑢  →  ( 𝑌  =  [ 𝑞 ] 𝑆  ↔  𝑌  =  [ 𝑢 ] 𝑆 ) ) | 
						
							| 61 | 60 | anbi2d | ⊢ ( 𝑞  =  𝑢  →  ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ↔  ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑢 ] 𝑆 ) ) ) | 
						
							| 62 |  | oveq2 | ⊢ ( 𝑞  =  𝑢  →  ( 𝑠  +  𝑞 )  =  ( 𝑠  +  𝑢 ) ) | 
						
							| 63 | 62 | eceq1d | ⊢ ( 𝑞  =  𝑢  →  [ ( 𝑠  +  𝑞 ) ] 𝑇  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) | 
						
							| 64 | 63 | eqeq2d | ⊢ ( 𝑞  =  𝑢  →  ( 𝑤  =  [ ( 𝑠  +  𝑞 ) ] 𝑇  ↔  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) ) | 
						
							| 65 | 61 64 | anbi12d | ⊢ ( 𝑞  =  𝑢  →  ( ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑞 ) ] 𝑇 )  ↔  ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) ) ) | 
						
							| 66 | 58 65 | cbvrex2vw | ⊢ ( ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ↔  ∃ 𝑠  ∈  𝐴 ∃ 𝑢  ∈  𝐵 ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) ) | 
						
							| 67 | 51 66 | anbi12i | ⊢ ( ( ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ∧  ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) )  ↔  ( ∃ 𝑟  ∈  𝐴 ∃ 𝑡  ∈  𝐵 ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑟  +  𝑡 ) ] 𝑇 )  ∧  ∃ 𝑠  ∈  𝐴 ∃ 𝑢  ∈  𝐵 ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) ) ) | 
						
							| 68 | 36 67 | bitr4i | ⊢ ( ∃ 𝑟  ∈  𝐴 ∃ 𝑠  ∈  𝐴 ( ∃ 𝑡  ∈  𝐵 ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑟  +  𝑡 ) ] 𝑇 )  ∧  ∃ 𝑢  ∈  𝐵 ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) )  ↔  ( ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ∧  ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) ) ) | 
						
							| 69 |  | reeanv | ⊢ ( ∃ 𝑡  ∈  𝐵 ∃ 𝑢  ∈  𝐵 ( ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑟  +  𝑡 ) ] 𝑇 )  ∧  ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) )  ↔  ( ∃ 𝑡  ∈  𝐵 ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑟  +  𝑡 ) ] 𝑇 )  ∧  ∃ 𝑢  ∈  𝐵 ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) ) ) | 
						
							| 70 | 4 | adantr | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  𝑅  Er  𝑈 ) | 
						
							| 71 | 7 | adantr | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  𝐴  ⊆  𝑈 ) | 
						
							| 72 |  | simprll | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  𝑟  ∈  𝐴 ) | 
						
							| 73 | 71 72 | sseldd | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  𝑟  ∈  𝑈 ) | 
						
							| 74 | 70 73 | erth | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  ( 𝑟 𝑅 𝑠  ↔  [ 𝑟 ] 𝑅  =  [ 𝑠 ] 𝑅 ) ) | 
						
							| 75 | 5 | adantr | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  𝑆  Er  𝑉 ) | 
						
							| 76 | 8 | adantr | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  𝐵  ⊆  𝑉 ) | 
						
							| 77 |  | simprrl | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  𝑡  ∈  𝐵 ) | 
						
							| 78 | 76 77 | sseldd | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  𝑡  ∈  𝑉 ) | 
						
							| 79 | 75 78 | erth | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  ( 𝑡 𝑆 𝑢  ↔  [ 𝑡 ] 𝑆  =  [ 𝑢 ] 𝑆 ) ) | 
						
							| 80 | 74 79 | anbi12d | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  ( ( 𝑟 𝑅 𝑠  ∧  𝑡 𝑆 𝑢 )  ↔  ( [ 𝑟 ] 𝑅  =  [ 𝑠 ] 𝑅  ∧  [ 𝑡 ] 𝑆  =  [ 𝑢 ] 𝑆 ) ) ) | 
						
							| 81 | 6 | adantr | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  𝑇  Er  𝑊 ) | 
						
							| 82 | 9 | adantr | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  𝐶  ⊆  𝑊 ) | 
						
							| 83 | 10 | adantr | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →   +  : ( 𝐴  ×  𝐵 ) ⟶ 𝐶 ) | 
						
							| 84 | 83 72 77 | fovcdmd | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  ( 𝑟  +  𝑡 )  ∈  𝐶 ) | 
						
							| 85 | 82 84 | sseldd | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  ( 𝑟  +  𝑡 )  ∈  𝑊 ) | 
						
							| 86 | 81 85 | erth | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  ( ( 𝑟  +  𝑡 ) 𝑇 ( 𝑠  +  𝑢 )  ↔  [ ( 𝑟  +  𝑡 ) ] 𝑇  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) ) | 
						
							| 87 | 11 80 86 | 3imtr3d | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  ( ( [ 𝑟 ] 𝑅  =  [ 𝑠 ] 𝑅  ∧  [ 𝑡 ] 𝑆  =  [ 𝑢 ] 𝑆 )  →  [ ( 𝑟  +  𝑡 ) ] 𝑇  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) ) | 
						
							| 88 |  | eqeq2 | ⊢ ( 𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇  →  ( [ ( 𝑟  +  𝑡 ) ] 𝑇  =  𝑤  ↔  [ ( 𝑟  +  𝑡 ) ] 𝑇  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) ) | 
						
							| 89 | 88 | biimprcd | ⊢ ( [ ( 𝑟  +  𝑡 ) ] 𝑇  =  [ ( 𝑠  +  𝑢 ) ] 𝑇  →  ( 𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇  →  [ ( 𝑟  +  𝑡 ) ] 𝑇  =  𝑤 ) ) | 
						
							| 90 | 87 89 | syl6 | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  ( ( [ 𝑟 ] 𝑅  =  [ 𝑠 ] 𝑅  ∧  [ 𝑡 ] 𝑆  =  [ 𝑢 ] 𝑆 )  →  ( 𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇  →  [ ( 𝑟  +  𝑡 ) ] 𝑇  =  𝑤 ) ) ) | 
						
							| 91 | 90 | impd | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  ( ( ( [ 𝑟 ] 𝑅  =  [ 𝑠 ] 𝑅  ∧  [ 𝑡 ] 𝑆  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 )  →  [ ( 𝑟  +  𝑡 ) ] 𝑇  =  𝑤 ) ) | 
						
							| 92 |  | eqeq1 | ⊢ ( 𝑋  =  [ 𝑟 ] 𝑅  →  ( 𝑋  =  [ 𝑠 ] 𝑅  ↔  [ 𝑟 ] 𝑅  =  [ 𝑠 ] 𝑅 ) ) | 
						
							| 93 |  | eqeq1 | ⊢ ( 𝑌  =  [ 𝑡 ] 𝑆  →  ( 𝑌  =  [ 𝑢 ] 𝑆  ↔  [ 𝑡 ] 𝑆  =  [ 𝑢 ] 𝑆 ) ) | 
						
							| 94 | 92 93 | bi2anan9 | ⊢ ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 )  →  ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑢 ] 𝑆 )  ↔  ( [ 𝑟 ] 𝑅  =  [ 𝑠 ] 𝑅  ∧  [ 𝑡 ] 𝑆  =  [ 𝑢 ] 𝑆 ) ) ) | 
						
							| 95 | 94 | anbi1d | ⊢ ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 )  →  ( ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 )  ↔  ( ( [ 𝑟 ] 𝑅  =  [ 𝑠 ] 𝑅  ∧  [ 𝑡 ] 𝑆  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) ) ) | 
						
							| 96 | 95 | adantr | ⊢ ( ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑟  +  𝑡 ) ] 𝑇 )  →  ( ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 )  ↔  ( ( [ 𝑟 ] 𝑅  =  [ 𝑠 ] 𝑅  ∧  [ 𝑡 ] 𝑆  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) ) ) | 
						
							| 97 |  | eqeq1 | ⊢ ( 𝑧  =  [ ( 𝑟  +  𝑡 ) ] 𝑇  →  ( 𝑧  =  𝑤  ↔  [ ( 𝑟  +  𝑡 ) ] 𝑇  =  𝑤 ) ) | 
						
							| 98 | 97 | adantl | ⊢ ( ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑟  +  𝑡 ) ] 𝑇 )  →  ( 𝑧  =  𝑤  ↔  [ ( 𝑟  +  𝑡 ) ] 𝑇  =  𝑤 ) ) | 
						
							| 99 | 96 98 | imbi12d | ⊢ ( ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑟  +  𝑡 ) ] 𝑇 )  →  ( ( ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 )  →  𝑧  =  𝑤 )  ↔  ( ( ( [ 𝑟 ] 𝑅  =  [ 𝑠 ] 𝑅  ∧  [ 𝑡 ] 𝑆  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 )  →  [ ( 𝑟  +  𝑡 ) ] 𝑇  =  𝑤 ) ) ) | 
						
							| 100 | 91 99 | syl5ibrcom | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  ( ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑟  +  𝑡 ) ] 𝑇 )  →  ( ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 )  →  𝑧  =  𝑤 ) ) ) | 
						
							| 101 | 100 | impd | ⊢ ( ( 𝜑  ∧  ( ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) ) )  →  ( ( ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑟  +  𝑡 ) ] 𝑇 )  ∧  ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) )  →  𝑧  =  𝑤 ) ) | 
						
							| 102 | 101 | anassrs | ⊢ ( ( ( 𝜑  ∧  ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 ) )  ∧  ( 𝑡  ∈  𝐵  ∧  𝑢  ∈  𝐵 ) )  →  ( ( ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑟  +  𝑡 ) ] 𝑇 )  ∧  ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) )  →  𝑧  =  𝑤 ) ) | 
						
							| 103 | 102 | rexlimdvva | ⊢ ( ( 𝜑  ∧  ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 ) )  →  ( ∃ 𝑡  ∈  𝐵 ∃ 𝑢  ∈  𝐵 ( ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑟  +  𝑡 ) ] 𝑇 )  ∧  ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) )  →  𝑧  =  𝑤 ) ) | 
						
							| 104 | 69 103 | biimtrrid | ⊢ ( ( 𝜑  ∧  ( 𝑟  ∈  𝐴  ∧  𝑠  ∈  𝐴 ) )  →  ( ( ∃ 𝑡  ∈  𝐵 ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑟  +  𝑡 ) ] 𝑇 )  ∧  ∃ 𝑢  ∈  𝐵 ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) )  →  𝑧  =  𝑤 ) ) | 
						
							| 105 | 104 | rexlimdvva | ⊢ ( 𝜑  →  ( ∃ 𝑟  ∈  𝐴 ∃ 𝑠  ∈  𝐴 ( ∃ 𝑡  ∈  𝐵 ( ( 𝑋  =  [ 𝑟 ] 𝑅  ∧  𝑌  =  [ 𝑡 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑟  +  𝑡 ) ] 𝑇 )  ∧  ∃ 𝑢  ∈  𝐵 ( ( 𝑋  =  [ 𝑠 ] 𝑅  ∧  𝑌  =  [ 𝑢 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑠  +  𝑢 ) ] 𝑇 ) )  →  𝑧  =  𝑤 ) ) | 
						
							| 106 | 68 105 | biimtrrid | ⊢ ( 𝜑  →  ( ( ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ∧  ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) )  →  𝑧  =  𝑤 ) ) | 
						
							| 107 | 106 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑋  ∈  𝐽  ∧  𝑌  ∈  𝐾 ) )  →  ( ( ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ∧  ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) )  →  𝑧  =  𝑤 ) ) | 
						
							| 108 | 107 | alrimivv | ⊢ ( ( 𝜑  ∧  ( 𝑋  ∈  𝐽  ∧  𝑌  ∈  𝐾 ) )  →  ∀ 𝑧 ∀ 𝑤 ( ( ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ∧  ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) )  →  𝑧  =  𝑤 ) ) | 
						
							| 109 |  | eqeq1 | ⊢ ( 𝑧  =  𝑤  →  ( 𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇  ↔  𝑤  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) ) | 
						
							| 110 | 109 | anbi2d | ⊢ ( 𝑧  =  𝑤  →  ( ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ↔  ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) ) ) | 
						
							| 111 | 110 | 2rexbidv | ⊢ ( 𝑧  =  𝑤  →  ( ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ↔  ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) ) ) | 
						
							| 112 | 111 | eu4 | ⊢ ( ∃! 𝑧 ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ↔  ( ∃ 𝑧 ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ∧  ∀ 𝑧 ∀ 𝑤 ( ( ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 )  ∧  ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑤  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) )  →  𝑧  =  𝑤 ) ) ) | 
						
							| 113 | 35 108 112 | sylanbrc | ⊢ ( ( 𝜑  ∧  ( 𝑋  ∈  𝐽  ∧  𝑌  ∈  𝐾 ) )  →  ∃! 𝑧 ∃ 𝑝  ∈  𝐴 ∃ 𝑞  ∈  𝐵 ( ( 𝑋  =  [ 𝑝 ] 𝑅  ∧  𝑌  =  [ 𝑞 ] 𝑆 )  ∧  𝑧  =  [ ( 𝑝  +  𝑞 ) ] 𝑇 ) ) |