| Step | Hyp | Ref | Expression | 
						
							| 1 |  | smat.s | ⊢ 𝑆  =  ( 𝐾 ( subMat1 ‘ 𝐴 ) 𝐿 ) | 
						
							| 2 |  | smat.m | ⊢ ( 𝜑  →  𝑀  ∈  ℕ ) | 
						
							| 3 |  | smat.n | ⊢ ( 𝜑  →  𝑁  ∈  ℕ ) | 
						
							| 4 |  | smat.k | ⊢ ( 𝜑  →  𝐾  ∈  ( 1 ... 𝑀 ) ) | 
						
							| 5 |  | smat.l | ⊢ ( 𝜑  →  𝐿  ∈  ( 1 ... 𝑁 ) ) | 
						
							| 6 |  | smat.a | ⊢ ( 𝜑  →  𝐴  ∈  ( 𝐵  ↑m  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) ) ) | 
						
							| 7 |  | elmapi | ⊢ ( 𝐴  ∈  ( 𝐵  ↑m  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) )  →  𝐴 : ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) ⟶ 𝐵 ) | 
						
							| 8 |  | ffun | ⊢ ( 𝐴 : ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) ⟶ 𝐵  →  Fun  𝐴 ) | 
						
							| 9 | 6 7 8 | 3syl | ⊢ ( 𝜑  →  Fun  𝐴 ) | 
						
							| 10 |  | eqid | ⊢ ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 )  =  ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) | 
						
							| 11 | 10 | mpofun | ⊢ Fun  ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) | 
						
							| 12 | 11 | a1i | ⊢ ( 𝜑  →  Fun  ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ) | 
						
							| 13 |  | funco | ⊢ ( ( Fun  𝐴  ∧  Fun  ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) )  →  Fun  ( 𝐴  ∘  ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ) ) | 
						
							| 14 | 9 12 13 | syl2anc | ⊢ ( 𝜑  →  Fun  ( 𝐴  ∘  ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ) ) | 
						
							| 15 |  | fz1ssnn | ⊢ ( 1 ... 𝑀 )  ⊆  ℕ | 
						
							| 16 | 15 4 | sselid | ⊢ ( 𝜑  →  𝐾  ∈  ℕ ) | 
						
							| 17 |  | fz1ssnn | ⊢ ( 1 ... 𝑁 )  ⊆  ℕ | 
						
							| 18 | 17 5 | sselid | ⊢ ( 𝜑  →  𝐿  ∈  ℕ ) | 
						
							| 19 |  | smatfval | ⊢ ( ( 𝐾  ∈  ℕ  ∧  𝐿  ∈  ℕ  ∧  𝐴  ∈  ( 𝐵  ↑m  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) ) )  →  ( 𝐾 ( subMat1 ‘ 𝐴 ) 𝐿 )  =  ( 𝐴  ∘  ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ) ) | 
						
							| 20 | 16 18 6 19 | syl3anc | ⊢ ( 𝜑  →  ( 𝐾 ( subMat1 ‘ 𝐴 ) 𝐿 )  =  ( 𝐴  ∘  ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ) ) | 
						
							| 21 | 1 20 | eqtrid | ⊢ ( 𝜑  →  𝑆  =  ( 𝐴  ∘  ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ) ) | 
						
							| 22 | 21 | funeqd | ⊢ ( 𝜑  →  ( Fun  𝑆  ↔  Fun  ( 𝐴  ∘  ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ) ) ) | 
						
							| 23 | 14 22 | mpbird | ⊢ ( 𝜑  →  Fun  𝑆 ) | 
						
							| 24 |  | fdmrn | ⊢ ( Fun  𝑆  ↔  𝑆 : dom  𝑆 ⟶ ran  𝑆 ) | 
						
							| 25 | 23 24 | sylib | ⊢ ( 𝜑  →  𝑆 : dom  𝑆 ⟶ ran  𝑆 ) | 
						
							| 26 | 21 | dmeqd | ⊢ ( 𝜑  →  dom  𝑆  =  dom  ( 𝐴  ∘  ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ) ) | 
						
							| 27 |  | dmco | ⊢ dom  ( 𝐴  ∘  ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) )  =  ( ◡ ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 )  “  dom  𝐴 ) | 
						
							| 28 |  | fdm | ⊢ ( 𝐴 : ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) ⟶ 𝐵  →  dom  𝐴  =  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) ) | 
						
							| 29 | 6 7 28 | 3syl | ⊢ ( 𝜑  →  dom  𝐴  =  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) ) | 
						
							| 30 | 29 | imaeq2d | ⊢ ( 𝜑  →  ( ◡ ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 )  “  dom  𝐴 )  =  ( ◡ ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 )  “  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) ) ) | 
						
							| 31 | 30 | eleq2d | ⊢ ( 𝜑  →  ( 𝑥  ∈  ( ◡ ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 )  “  dom  𝐴 )  ↔  𝑥  ∈  ( ◡ ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 )  “  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) ) ) ) | 
						
							| 32 |  | opex | ⊢ 〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉  ∈  V | 
						
							| 33 | 10 32 | fnmpoi | ⊢ ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 )  Fn  ( ℕ  ×  ℕ ) | 
						
							| 34 |  | elpreima | ⊢ ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 )  Fn  ( ℕ  ×  ℕ )  →  ( 𝑥  ∈  ( ◡ ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 )  “  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) )  ↔  ( 𝑥  ∈  ( ℕ  ×  ℕ )  ∧  ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 𝑥 )  ∈  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) ) ) ) | 
						
							| 35 | 33 34 | ax-mp | ⊢ ( 𝑥  ∈  ( ◡ ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 )  “  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) )  ↔  ( 𝑥  ∈  ( ℕ  ×  ℕ )  ∧  ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 𝑥 )  ∈  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) ) ) | 
						
							| 36 | 35 | a1i | ⊢ ( 𝜑  →  ( 𝑥  ∈  ( ◡ ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 )  “  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) )  ↔  ( 𝑥  ∈  ( ℕ  ×  ℕ )  ∧  ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 𝑥 )  ∈  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) ) ) ) | 
						
							| 37 |  | simplr | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 ) | 
						
							| 38 | 37 | fveq2d | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 𝑥 )  =  ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 ) ) | 
						
							| 39 |  | df-ov | ⊢ ( ( 1st  ‘ 𝑥 ) ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ( 2nd  ‘ 𝑥 ) )  =  ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 ) | 
						
							| 40 | 38 39 | eqtr4di | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 𝑥 )  =  ( ( 1st  ‘ 𝑥 ) ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ( 2nd  ‘ 𝑥 ) ) ) | 
						
							| 41 |  | breq1 | ⊢ ( 𝑖  =  ( 1st  ‘ 𝑥 )  →  ( 𝑖  <  𝐾  ↔  ( 1st  ‘ 𝑥 )  <  𝐾 ) ) | 
						
							| 42 |  | id | ⊢ ( 𝑖  =  ( 1st  ‘ 𝑥 )  →  𝑖  =  ( 1st  ‘ 𝑥 ) ) | 
						
							| 43 |  | oveq1 | ⊢ ( 𝑖  =  ( 1st  ‘ 𝑥 )  →  ( 𝑖  +  1 )  =  ( ( 1st  ‘ 𝑥 )  +  1 ) ) | 
						
							| 44 | 41 42 43 | ifbieq12d | ⊢ ( 𝑖  =  ( 1st  ‘ 𝑥 )  →  if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) )  =  if ( ( 1st  ‘ 𝑥 )  <  𝐾 ,  ( 1st  ‘ 𝑥 ) ,  ( ( 1st  ‘ 𝑥 )  +  1 ) ) ) | 
						
							| 45 | 44 | opeq1d | ⊢ ( 𝑖  =  ( 1st  ‘ 𝑥 )  →  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉  =  〈 if ( ( 1st  ‘ 𝑥 )  <  𝐾 ,  ( 1st  ‘ 𝑥 ) ,  ( ( 1st  ‘ 𝑥 )  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) | 
						
							| 46 |  | breq1 | ⊢ ( 𝑗  =  ( 2nd  ‘ 𝑥 )  →  ( 𝑗  <  𝐿  ↔  ( 2nd  ‘ 𝑥 )  <  𝐿 ) ) | 
						
							| 47 |  | id | ⊢ ( 𝑗  =  ( 2nd  ‘ 𝑥 )  →  𝑗  =  ( 2nd  ‘ 𝑥 ) ) | 
						
							| 48 |  | oveq1 | ⊢ ( 𝑗  =  ( 2nd  ‘ 𝑥 )  →  ( 𝑗  +  1 )  =  ( ( 2nd  ‘ 𝑥 )  +  1 ) ) | 
						
							| 49 | 46 47 48 | ifbieq12d | ⊢ ( 𝑗  =  ( 2nd  ‘ 𝑥 )  →  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) )  =  if ( ( 2nd  ‘ 𝑥 )  <  𝐿 ,  ( 2nd  ‘ 𝑥 ) ,  ( ( 2nd  ‘ 𝑥 )  +  1 ) ) ) | 
						
							| 50 | 49 | opeq2d | ⊢ ( 𝑗  =  ( 2nd  ‘ 𝑥 )  →  〈 if ( ( 1st  ‘ 𝑥 )  <  𝐾 ,  ( 1st  ‘ 𝑥 ) ,  ( ( 1st  ‘ 𝑥 )  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉  =  〈 if ( ( 1st  ‘ 𝑥 )  <  𝐾 ,  ( 1st  ‘ 𝑥 ) ,  ( ( 1st  ‘ 𝑥 )  +  1 ) ) ,  if ( ( 2nd  ‘ 𝑥 )  <  𝐿 ,  ( 2nd  ‘ 𝑥 ) ,  ( ( 2nd  ‘ 𝑥 )  +  1 ) ) 〉 ) | 
						
							| 51 |  | opex | ⊢ 〈 if ( ( 1st  ‘ 𝑥 )  <  𝐾 ,  ( 1st  ‘ 𝑥 ) ,  ( ( 1st  ‘ 𝑥 )  +  1 ) ) ,  if ( ( 2nd  ‘ 𝑥 )  <  𝐿 ,  ( 2nd  ‘ 𝑥 ) ,  ( ( 2nd  ‘ 𝑥 )  +  1 ) ) 〉  ∈  V | 
						
							| 52 | 45 50 10 51 | ovmpo | ⊢ ( ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ )  →  ( ( 1st  ‘ 𝑥 ) ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ( 2nd  ‘ 𝑥 ) )  =  〈 if ( ( 1st  ‘ 𝑥 )  <  𝐾 ,  ( 1st  ‘ 𝑥 ) ,  ( ( 1st  ‘ 𝑥 )  +  1 ) ) ,  if ( ( 2nd  ‘ 𝑥 )  <  𝐿 ,  ( 2nd  ‘ 𝑥 ) ,  ( ( 2nd  ‘ 𝑥 )  +  1 ) ) 〉 ) | 
						
							| 53 | 52 | adantl | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( 1st  ‘ 𝑥 ) ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ( 2nd  ‘ 𝑥 ) )  =  〈 if ( ( 1st  ‘ 𝑥 )  <  𝐾 ,  ( 1st  ‘ 𝑥 ) ,  ( ( 1st  ‘ 𝑥 )  +  1 ) ) ,  if ( ( 2nd  ‘ 𝑥 )  <  𝐿 ,  ( 2nd  ‘ 𝑥 ) ,  ( ( 2nd  ‘ 𝑥 )  +  1 ) ) 〉 ) | 
						
							| 54 | 40 53 | eqtrd | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 𝑥 )  =  〈 if ( ( 1st  ‘ 𝑥 )  <  𝐾 ,  ( 1st  ‘ 𝑥 ) ,  ( ( 1st  ‘ 𝑥 )  +  1 ) ) ,  if ( ( 2nd  ‘ 𝑥 )  <  𝐿 ,  ( 2nd  ‘ 𝑥 ) ,  ( ( 2nd  ‘ 𝑥 )  +  1 ) ) 〉 ) | 
						
							| 55 | 54 | eleq1d | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 𝑥 )  ∈  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) )  ↔  〈 if ( ( 1st  ‘ 𝑥 )  <  𝐾 ,  ( 1st  ‘ 𝑥 ) ,  ( ( 1st  ‘ 𝑥 )  +  1 ) ) ,  if ( ( 2nd  ‘ 𝑥 )  <  𝐿 ,  ( 2nd  ‘ 𝑥 ) ,  ( ( 2nd  ‘ 𝑥 )  +  1 ) ) 〉  ∈  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) ) ) | 
						
							| 56 |  | opelxp | ⊢ ( 〈 if ( ( 1st  ‘ 𝑥 )  <  𝐾 ,  ( 1st  ‘ 𝑥 ) ,  ( ( 1st  ‘ 𝑥 )  +  1 ) ) ,  if ( ( 2nd  ‘ 𝑥 )  <  𝐿 ,  ( 2nd  ‘ 𝑥 ) ,  ( ( 2nd  ‘ 𝑥 )  +  1 ) ) 〉  ∈  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) )  ↔  ( if ( ( 1st  ‘ 𝑥 )  <  𝐾 ,  ( 1st  ‘ 𝑥 ) ,  ( ( 1st  ‘ 𝑥 )  +  1 ) )  ∈  ( 1 ... 𝑀 )  ∧  if ( ( 2nd  ‘ 𝑥 )  <  𝐿 ,  ( 2nd  ‘ 𝑥 ) ,  ( ( 2nd  ‘ 𝑥 )  +  1 ) )  ∈  ( 1 ... 𝑁 ) ) ) | 
						
							| 57 | 55 56 | bitrdi | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 𝑥 )  ∈  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) )  ↔  ( if ( ( 1st  ‘ 𝑥 )  <  𝐾 ,  ( 1st  ‘ 𝑥 ) ,  ( ( 1st  ‘ 𝑥 )  +  1 ) )  ∈  ( 1 ... 𝑀 )  ∧  if ( ( 2nd  ‘ 𝑥 )  <  𝐿 ,  ( 2nd  ‘ 𝑥 ) ,  ( ( 2nd  ‘ 𝑥 )  +  1 ) )  ∈  ( 1 ... 𝑁 ) ) ) ) | 
						
							| 58 |  | ifel | ⊢ ( if ( ( 1st  ‘ 𝑥 )  <  𝐾 ,  ( 1st  ‘ 𝑥 ) ,  ( ( 1st  ‘ 𝑥 )  +  1 ) )  ∈  ( 1 ... 𝑀 )  ↔  ( ( ( 1st  ‘ 𝑥 )  <  𝐾  ∧  ( 1st  ‘ 𝑥 )  ∈  ( 1 ... 𝑀 ) )  ∨  ( ¬  ( 1st  ‘ 𝑥 )  <  𝐾  ∧  ( ( 1st  ‘ 𝑥 )  +  1 )  ∈  ( 1 ... 𝑀 ) ) ) ) | 
						
							| 59 |  | simplrl | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 1st  ‘ 𝑥 )  <  𝐾 )  →  ( 1st  ‘ 𝑥 )  ∈  ℕ ) | 
						
							| 60 | 59 | nnred | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 1st  ‘ 𝑥 )  <  𝐾 )  →  ( 1st  ‘ 𝑥 )  ∈  ℝ ) | 
						
							| 61 | 16 | nnred | ⊢ ( 𝜑  →  𝐾  ∈  ℝ ) | 
						
							| 62 | 61 | ad3antrrr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 1st  ‘ 𝑥 )  <  𝐾 )  →  𝐾  ∈  ℝ ) | 
						
							| 63 | 2 | nnred | ⊢ ( 𝜑  →  𝑀  ∈  ℝ ) | 
						
							| 64 | 63 | ad3antrrr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 1st  ‘ 𝑥 )  <  𝐾 )  →  𝑀  ∈  ℝ ) | 
						
							| 65 |  | simpr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 1st  ‘ 𝑥 )  <  𝐾 )  →  ( 1st  ‘ 𝑥 )  <  𝐾 ) | 
						
							| 66 | 60 62 65 | ltled | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 1st  ‘ 𝑥 )  <  𝐾 )  →  ( 1st  ‘ 𝑥 )  ≤  𝐾 ) | 
						
							| 67 |  | elfzle2 | ⊢ ( 𝐾  ∈  ( 1 ... 𝑀 )  →  𝐾  ≤  𝑀 ) | 
						
							| 68 | 4 67 | syl | ⊢ ( 𝜑  →  𝐾  ≤  𝑀 ) | 
						
							| 69 | 68 | ad3antrrr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 1st  ‘ 𝑥 )  <  𝐾 )  →  𝐾  ≤  𝑀 ) | 
						
							| 70 | 60 62 64 66 69 | letrd | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 1st  ‘ 𝑥 )  <  𝐾 )  →  ( 1st  ‘ 𝑥 )  ≤  𝑀 ) | 
						
							| 71 | 59 70 | jca | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 1st  ‘ 𝑥 )  <  𝐾 )  →  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 1st  ‘ 𝑥 )  ≤  𝑀 ) ) | 
						
							| 72 | 2 | nnzd | ⊢ ( 𝜑  →  𝑀  ∈  ℤ ) | 
						
							| 73 |  | fznn | ⊢ ( 𝑀  ∈  ℤ  →  ( ( 1st  ‘ 𝑥 )  ∈  ( 1 ... 𝑀 )  ↔  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 1st  ‘ 𝑥 )  ≤  𝑀 ) ) ) | 
						
							| 74 | 72 73 | syl | ⊢ ( 𝜑  →  ( ( 1st  ‘ 𝑥 )  ∈  ( 1 ... 𝑀 )  ↔  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 1st  ‘ 𝑥 )  ≤  𝑀 ) ) ) | 
						
							| 75 | 74 | ad3antrrr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 1st  ‘ 𝑥 )  <  𝐾 )  →  ( ( 1st  ‘ 𝑥 )  ∈  ( 1 ... 𝑀 )  ↔  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 1st  ‘ 𝑥 )  ≤  𝑀 ) ) ) | 
						
							| 76 | 71 75 | mpbird | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 1st  ‘ 𝑥 )  <  𝐾 )  →  ( 1st  ‘ 𝑥 )  ∈  ( 1 ... 𝑀 ) ) | 
						
							| 77 | 60 62 64 65 69 | ltletrd | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 1st  ‘ 𝑥 )  <  𝐾 )  →  ( 1st  ‘ 𝑥 )  <  𝑀 ) | 
						
							| 78 | 2 | ad3antrrr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 1st  ‘ 𝑥 )  <  𝐾 )  →  𝑀  ∈  ℕ ) | 
						
							| 79 |  | nnltlem1 | ⊢ ( ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  𝑀  ∈  ℕ )  →  ( ( 1st  ‘ 𝑥 )  <  𝑀  ↔  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) ) ) | 
						
							| 80 | 59 78 79 | syl2anc | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 1st  ‘ 𝑥 )  <  𝐾 )  →  ( ( 1st  ‘ 𝑥 )  <  𝑀  ↔  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) ) ) | 
						
							| 81 | 77 80 | mpbid | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 1st  ‘ 𝑥 )  <  𝐾 )  →  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) ) | 
						
							| 82 | 76 81 | 2thd | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 1st  ‘ 𝑥 )  <  𝐾 )  →  ( ( 1st  ‘ 𝑥 )  ∈  ( 1 ... 𝑀 )  ↔  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) ) ) | 
						
							| 83 | 82 | pm5.32da | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( ( 1st  ‘ 𝑥 )  <  𝐾  ∧  ( 1st  ‘ 𝑥 )  ∈  ( 1 ... 𝑀 ) )  ↔  ( ( 1st  ‘ 𝑥 )  <  𝐾  ∧  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) ) ) ) | 
						
							| 84 |  | fznn | ⊢ ( 𝑀  ∈  ℤ  →  ( ( ( 1st  ‘ 𝑥 )  +  1 )  ∈  ( 1 ... 𝑀 )  ↔  ( ( ( 1st  ‘ 𝑥 )  +  1 )  ∈  ℕ  ∧  ( ( 1st  ‘ 𝑥 )  +  1 )  ≤  𝑀 ) ) ) | 
						
							| 85 | 72 84 | syl | ⊢ ( 𝜑  →  ( ( ( 1st  ‘ 𝑥 )  +  1 )  ∈  ( 1 ... 𝑀 )  ↔  ( ( ( 1st  ‘ 𝑥 )  +  1 )  ∈  ℕ  ∧  ( ( 1st  ‘ 𝑥 )  +  1 )  ≤  𝑀 ) ) ) | 
						
							| 86 | 85 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( ( 1st  ‘ 𝑥 )  +  1 )  ∈  ( 1 ... 𝑀 )  ↔  ( ( ( 1st  ‘ 𝑥 )  +  1 )  ∈  ℕ  ∧  ( ( 1st  ‘ 𝑥 )  +  1 )  ≤  𝑀 ) ) ) | 
						
							| 87 |  | simprl | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( 1st  ‘ 𝑥 )  ∈  ℕ ) | 
						
							| 88 | 87 | peano2nnd | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( 1st  ‘ 𝑥 )  +  1 )  ∈  ℕ ) | 
						
							| 89 | 88 | biantrurd | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( ( 1st  ‘ 𝑥 )  +  1 )  ≤  𝑀  ↔  ( ( ( 1st  ‘ 𝑥 )  +  1 )  ∈  ℕ  ∧  ( ( 1st  ‘ 𝑥 )  +  1 )  ≤  𝑀 ) ) ) | 
						
							| 90 | 87 | nnzd | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( 1st  ‘ 𝑥 )  ∈  ℤ ) | 
						
							| 91 | 72 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  𝑀  ∈  ℤ ) | 
						
							| 92 |  | zltp1le | ⊢ ( ( ( 1st  ‘ 𝑥 )  ∈  ℤ  ∧  𝑀  ∈  ℤ )  →  ( ( 1st  ‘ 𝑥 )  <  𝑀  ↔  ( ( 1st  ‘ 𝑥 )  +  1 )  ≤  𝑀 ) ) | 
						
							| 93 |  | zltlem1 | ⊢ ( ( ( 1st  ‘ 𝑥 )  ∈  ℤ  ∧  𝑀  ∈  ℤ )  →  ( ( 1st  ‘ 𝑥 )  <  𝑀  ↔  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) ) ) | 
						
							| 94 | 92 93 | bitr3d | ⊢ ( ( ( 1st  ‘ 𝑥 )  ∈  ℤ  ∧  𝑀  ∈  ℤ )  →  ( ( ( 1st  ‘ 𝑥 )  +  1 )  ≤  𝑀  ↔  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) ) ) | 
						
							| 95 | 90 91 94 | syl2anc | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( ( 1st  ‘ 𝑥 )  +  1 )  ≤  𝑀  ↔  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) ) ) | 
						
							| 96 | 86 89 95 | 3bitr2d | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( ( 1st  ‘ 𝑥 )  +  1 )  ∈  ( 1 ... 𝑀 )  ↔  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) ) ) | 
						
							| 97 | 96 | anbi2d | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( ¬  ( 1st  ‘ 𝑥 )  <  𝐾  ∧  ( ( 1st  ‘ 𝑥 )  +  1 )  ∈  ( 1 ... 𝑀 ) )  ↔  ( ¬  ( 1st  ‘ 𝑥 )  <  𝐾  ∧  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) ) ) ) | 
						
							| 98 | 83 97 | orbi12d | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( ( ( 1st  ‘ 𝑥 )  <  𝐾  ∧  ( 1st  ‘ 𝑥 )  ∈  ( 1 ... 𝑀 ) )  ∨  ( ¬  ( 1st  ‘ 𝑥 )  <  𝐾  ∧  ( ( 1st  ‘ 𝑥 )  +  1 )  ∈  ( 1 ... 𝑀 ) ) )  ↔  ( ( ( 1st  ‘ 𝑥 )  <  𝐾  ∧  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) )  ∨  ( ¬  ( 1st  ‘ 𝑥 )  <  𝐾  ∧  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) ) ) ) ) | 
						
							| 99 |  | pm4.42 | ⊢ ( ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 )  ↔  ( ( ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 )  ∧  ( 1st  ‘ 𝑥 )  <  𝐾 )  ∨  ( ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 )  ∧  ¬  ( 1st  ‘ 𝑥 )  <  𝐾 ) ) ) | 
						
							| 100 |  | ancom | ⊢ ( ( ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 )  ∧  ( 1st  ‘ 𝑥 )  <  𝐾 )  ↔  ( ( 1st  ‘ 𝑥 )  <  𝐾  ∧  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) ) ) | 
						
							| 101 |  | ancom | ⊢ ( ( ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 )  ∧  ¬  ( 1st  ‘ 𝑥 )  <  𝐾 )  ↔  ( ¬  ( 1st  ‘ 𝑥 )  <  𝐾  ∧  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) ) ) | 
						
							| 102 | 100 101 | orbi12i | ⊢ ( ( ( ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 )  ∧  ( 1st  ‘ 𝑥 )  <  𝐾 )  ∨  ( ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 )  ∧  ¬  ( 1st  ‘ 𝑥 )  <  𝐾 ) )  ↔  ( ( ( 1st  ‘ 𝑥 )  <  𝐾  ∧  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) )  ∨  ( ¬  ( 1st  ‘ 𝑥 )  <  𝐾  ∧  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) ) ) ) | 
						
							| 103 | 99 102 | bitri | ⊢ ( ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 )  ↔  ( ( ( 1st  ‘ 𝑥 )  <  𝐾  ∧  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) )  ∨  ( ¬  ( 1st  ‘ 𝑥 )  <  𝐾  ∧  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) ) ) ) | 
						
							| 104 | 98 103 | bitr4di | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( ( ( 1st  ‘ 𝑥 )  <  𝐾  ∧  ( 1st  ‘ 𝑥 )  ∈  ( 1 ... 𝑀 ) )  ∨  ( ¬  ( 1st  ‘ 𝑥 )  <  𝐾  ∧  ( ( 1st  ‘ 𝑥 )  +  1 )  ∈  ( 1 ... 𝑀 ) ) )  ↔  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) ) ) | 
						
							| 105 | 58 104 | bitrid | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( if ( ( 1st  ‘ 𝑥 )  <  𝐾 ,  ( 1st  ‘ 𝑥 ) ,  ( ( 1st  ‘ 𝑥 )  +  1 ) )  ∈  ( 1 ... 𝑀 )  ↔  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) ) ) | 
						
							| 106 |  | ifel | ⊢ ( if ( ( 2nd  ‘ 𝑥 )  <  𝐿 ,  ( 2nd  ‘ 𝑥 ) ,  ( ( 2nd  ‘ 𝑥 )  +  1 ) )  ∈  ( 1 ... 𝑁 )  ↔  ( ( ( 2nd  ‘ 𝑥 )  <  𝐿  ∧  ( 2nd  ‘ 𝑥 )  ∈  ( 1 ... 𝑁 ) )  ∨  ( ¬  ( 2nd  ‘ 𝑥 )  <  𝐿  ∧  ( ( 2nd  ‘ 𝑥 )  +  1 )  ∈  ( 1 ... 𝑁 ) ) ) ) | 
						
							| 107 |  | simplrr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 2nd  ‘ 𝑥 )  <  𝐿 )  →  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) | 
						
							| 108 | 107 | nnred | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 2nd  ‘ 𝑥 )  <  𝐿 )  →  ( 2nd  ‘ 𝑥 )  ∈  ℝ ) | 
						
							| 109 | 18 | nnred | ⊢ ( 𝜑  →  𝐿  ∈  ℝ ) | 
						
							| 110 | 109 | ad3antrrr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 2nd  ‘ 𝑥 )  <  𝐿 )  →  𝐿  ∈  ℝ ) | 
						
							| 111 | 3 | nnred | ⊢ ( 𝜑  →  𝑁  ∈  ℝ ) | 
						
							| 112 | 111 | ad3antrrr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 2nd  ‘ 𝑥 )  <  𝐿 )  →  𝑁  ∈  ℝ ) | 
						
							| 113 |  | simpr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 2nd  ‘ 𝑥 )  <  𝐿 )  →  ( 2nd  ‘ 𝑥 )  <  𝐿 ) | 
						
							| 114 | 108 110 113 | ltled | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 2nd  ‘ 𝑥 )  <  𝐿 )  →  ( 2nd  ‘ 𝑥 )  ≤  𝐿 ) | 
						
							| 115 |  | elfzle2 | ⊢ ( 𝐿  ∈  ( 1 ... 𝑁 )  →  𝐿  ≤  𝑁 ) | 
						
							| 116 | 5 115 | syl | ⊢ ( 𝜑  →  𝐿  ≤  𝑁 ) | 
						
							| 117 | 116 | ad3antrrr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 2nd  ‘ 𝑥 )  <  𝐿 )  →  𝐿  ≤  𝑁 ) | 
						
							| 118 | 108 110 112 114 117 | letrd | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 2nd  ‘ 𝑥 )  <  𝐿 )  →  ( 2nd  ‘ 𝑥 )  ≤  𝑁 ) | 
						
							| 119 | 107 118 | jca | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 2nd  ‘ 𝑥 )  <  𝐿 )  →  ( ( 2nd  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ≤  𝑁 ) ) | 
						
							| 120 | 3 | nnzd | ⊢ ( 𝜑  →  𝑁  ∈  ℤ ) | 
						
							| 121 |  | fznn | ⊢ ( 𝑁  ∈  ℤ  →  ( ( 2nd  ‘ 𝑥 )  ∈  ( 1 ... 𝑁 )  ↔  ( ( 2nd  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ≤  𝑁 ) ) ) | 
						
							| 122 | 120 121 | syl | ⊢ ( 𝜑  →  ( ( 2nd  ‘ 𝑥 )  ∈  ( 1 ... 𝑁 )  ↔  ( ( 2nd  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ≤  𝑁 ) ) ) | 
						
							| 123 | 122 | ad3antrrr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 2nd  ‘ 𝑥 )  <  𝐿 )  →  ( ( 2nd  ‘ 𝑥 )  ∈  ( 1 ... 𝑁 )  ↔  ( ( 2nd  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ≤  𝑁 ) ) ) | 
						
							| 124 | 119 123 | mpbird | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 2nd  ‘ 𝑥 )  <  𝐿 )  →  ( 2nd  ‘ 𝑥 )  ∈  ( 1 ... 𝑁 ) ) | 
						
							| 125 | 108 110 112 113 117 | ltletrd | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 2nd  ‘ 𝑥 )  <  𝐿 )  →  ( 2nd  ‘ 𝑥 )  <  𝑁 ) | 
						
							| 126 | 3 | ad3antrrr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 2nd  ‘ 𝑥 )  <  𝐿 )  →  𝑁  ∈  ℕ ) | 
						
							| 127 |  | nnltlem1 | ⊢ ( ( ( 2nd  ‘ 𝑥 )  ∈  ℕ  ∧  𝑁  ∈  ℕ )  →  ( ( 2nd  ‘ 𝑥 )  <  𝑁  ↔  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) | 
						
							| 128 | 107 126 127 | syl2anc | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 2nd  ‘ 𝑥 )  <  𝐿 )  →  ( ( 2nd  ‘ 𝑥 )  <  𝑁  ↔  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) | 
						
							| 129 | 125 128 | mpbid | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 2nd  ‘ 𝑥 )  <  𝐿 )  →  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) | 
						
							| 130 | 124 129 | 2thd | ⊢ ( ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( 2nd  ‘ 𝑥 )  <  𝐿 )  →  ( ( 2nd  ‘ 𝑥 )  ∈  ( 1 ... 𝑁 )  ↔  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) | 
						
							| 131 | 130 | pm5.32da | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( ( 2nd  ‘ 𝑥 )  <  𝐿  ∧  ( 2nd  ‘ 𝑥 )  ∈  ( 1 ... 𝑁 ) )  ↔  ( ( 2nd  ‘ 𝑥 )  <  𝐿  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) ) | 
						
							| 132 |  | fznn | ⊢ ( 𝑁  ∈  ℤ  →  ( ( ( 2nd  ‘ 𝑥 )  +  1 )  ∈  ( 1 ... 𝑁 )  ↔  ( ( ( 2nd  ‘ 𝑥 )  +  1 )  ∈  ℕ  ∧  ( ( 2nd  ‘ 𝑥 )  +  1 )  ≤  𝑁 ) ) ) | 
						
							| 133 | 120 132 | syl | ⊢ ( 𝜑  →  ( ( ( 2nd  ‘ 𝑥 )  +  1 )  ∈  ( 1 ... 𝑁 )  ↔  ( ( ( 2nd  ‘ 𝑥 )  +  1 )  ∈  ℕ  ∧  ( ( 2nd  ‘ 𝑥 )  +  1 )  ≤  𝑁 ) ) ) | 
						
							| 134 | 133 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( ( 2nd  ‘ 𝑥 )  +  1 )  ∈  ( 1 ... 𝑁 )  ↔  ( ( ( 2nd  ‘ 𝑥 )  +  1 )  ∈  ℕ  ∧  ( ( 2nd  ‘ 𝑥 )  +  1 )  ≤  𝑁 ) ) ) | 
						
							| 135 |  | simprr | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) | 
						
							| 136 | 135 | peano2nnd | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( 2nd  ‘ 𝑥 )  +  1 )  ∈  ℕ ) | 
						
							| 137 | 136 | biantrurd | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( ( 2nd  ‘ 𝑥 )  +  1 )  ≤  𝑁  ↔  ( ( ( 2nd  ‘ 𝑥 )  +  1 )  ∈  ℕ  ∧  ( ( 2nd  ‘ 𝑥 )  +  1 )  ≤  𝑁 ) ) ) | 
						
							| 138 | 135 | nnzd | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( 2nd  ‘ 𝑥 )  ∈  ℤ ) | 
						
							| 139 | 120 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  𝑁  ∈  ℤ ) | 
						
							| 140 |  | zltp1le | ⊢ ( ( ( 2nd  ‘ 𝑥 )  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  ( ( 2nd  ‘ 𝑥 )  <  𝑁  ↔  ( ( 2nd  ‘ 𝑥 )  +  1 )  ≤  𝑁 ) ) | 
						
							| 141 |  | zltlem1 | ⊢ ( ( ( 2nd  ‘ 𝑥 )  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  ( ( 2nd  ‘ 𝑥 )  <  𝑁  ↔  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) | 
						
							| 142 | 140 141 | bitr3d | ⊢ ( ( ( 2nd  ‘ 𝑥 )  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  ( ( ( 2nd  ‘ 𝑥 )  +  1 )  ≤  𝑁  ↔  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) | 
						
							| 143 | 138 139 142 | syl2anc | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( ( 2nd  ‘ 𝑥 )  +  1 )  ≤  𝑁  ↔  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) | 
						
							| 144 | 134 137 143 | 3bitr2d | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( ( 2nd  ‘ 𝑥 )  +  1 )  ∈  ( 1 ... 𝑁 )  ↔  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) | 
						
							| 145 | 144 | anbi2d | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( ¬  ( 2nd  ‘ 𝑥 )  <  𝐿  ∧  ( ( 2nd  ‘ 𝑥 )  +  1 )  ∈  ( 1 ... 𝑁 ) )  ↔  ( ¬  ( 2nd  ‘ 𝑥 )  <  𝐿  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) ) | 
						
							| 146 | 131 145 | orbi12d | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( ( ( 2nd  ‘ 𝑥 )  <  𝐿  ∧  ( 2nd  ‘ 𝑥 )  ∈  ( 1 ... 𝑁 ) )  ∨  ( ¬  ( 2nd  ‘ 𝑥 )  <  𝐿  ∧  ( ( 2nd  ‘ 𝑥 )  +  1 )  ∈  ( 1 ... 𝑁 ) ) )  ↔  ( ( ( 2nd  ‘ 𝑥 )  <  𝐿  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) )  ∨  ( ¬  ( 2nd  ‘ 𝑥 )  <  𝐿  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) ) ) | 
						
							| 147 |  | pm4.42 | ⊢ ( ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 )  ↔  ( ( ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 )  ∧  ( 2nd  ‘ 𝑥 )  <  𝐿 )  ∨  ( ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 )  ∧  ¬  ( 2nd  ‘ 𝑥 )  <  𝐿 ) ) ) | 
						
							| 148 |  | ancom | ⊢ ( ( ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 )  ∧  ( 2nd  ‘ 𝑥 )  <  𝐿 )  ↔  ( ( 2nd  ‘ 𝑥 )  <  𝐿  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) | 
						
							| 149 |  | ancom | ⊢ ( ( ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 )  ∧  ¬  ( 2nd  ‘ 𝑥 )  <  𝐿 )  ↔  ( ¬  ( 2nd  ‘ 𝑥 )  <  𝐿  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) | 
						
							| 150 | 148 149 | orbi12i | ⊢ ( ( ( ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 )  ∧  ( 2nd  ‘ 𝑥 )  <  𝐿 )  ∨  ( ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 )  ∧  ¬  ( 2nd  ‘ 𝑥 )  <  𝐿 ) )  ↔  ( ( ( 2nd  ‘ 𝑥 )  <  𝐿  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) )  ∨  ( ¬  ( 2nd  ‘ 𝑥 )  <  𝐿  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) ) | 
						
							| 151 | 147 150 | bitri | ⊢ ( ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 )  ↔  ( ( ( 2nd  ‘ 𝑥 )  <  𝐿  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) )  ∨  ( ¬  ( 2nd  ‘ 𝑥 )  <  𝐿  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) ) | 
						
							| 152 | 146 151 | bitr4di | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( ( ( 2nd  ‘ 𝑥 )  <  𝐿  ∧  ( 2nd  ‘ 𝑥 )  ∈  ( 1 ... 𝑁 ) )  ∨  ( ¬  ( 2nd  ‘ 𝑥 )  <  𝐿  ∧  ( ( 2nd  ‘ 𝑥 )  +  1 )  ∈  ( 1 ... 𝑁 ) ) )  ↔  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) | 
						
							| 153 | 106 152 | bitrid | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( if ( ( 2nd  ‘ 𝑥 )  <  𝐿 ,  ( 2nd  ‘ 𝑥 ) ,  ( ( 2nd  ‘ 𝑥 )  +  1 ) )  ∈  ( 1 ... 𝑁 )  ↔  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) | 
						
							| 154 | 105 153 | anbi12d | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( if ( ( 1st  ‘ 𝑥 )  <  𝐾 ,  ( 1st  ‘ 𝑥 ) ,  ( ( 1st  ‘ 𝑥 )  +  1 ) )  ∈  ( 1 ... 𝑀 )  ∧  if ( ( 2nd  ‘ 𝑥 )  <  𝐿 ,  ( 2nd  ‘ 𝑥 ) ,  ( ( 2nd  ‘ 𝑥 )  +  1 ) )  ∈  ( 1 ... 𝑁 ) )  ↔  ( ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 )  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) ) | 
						
							| 155 | 57 154 | bitrd | ⊢ ( ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  →  ( ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 𝑥 )  ∈  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) )  ↔  ( ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 )  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) ) | 
						
							| 156 | 155 | pm5.32da | ⊢ ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  →  ( ( ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ )  ∧  ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 𝑥 )  ∈  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) )  ↔  ( ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ )  ∧  ( ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 )  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) ) ) | 
						
							| 157 |  | 1zzd | ⊢ ( 𝜑  →  1  ∈  ℤ ) | 
						
							| 158 | 72 157 | zsubcld | ⊢ ( 𝜑  →  ( 𝑀  −  1 )  ∈  ℤ ) | 
						
							| 159 |  | fznn | ⊢ ( ( 𝑀  −  1 )  ∈  ℤ  →  ( ( 1st  ‘ 𝑥 )  ∈  ( 1 ... ( 𝑀  −  1 ) )  ↔  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) ) ) ) | 
						
							| 160 | 158 159 | syl | ⊢ ( 𝜑  →  ( ( 1st  ‘ 𝑥 )  ∈  ( 1 ... ( 𝑀  −  1 ) )  ↔  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) ) ) ) | 
						
							| 161 | 120 157 | zsubcld | ⊢ ( 𝜑  →  ( 𝑁  −  1 )  ∈  ℤ ) | 
						
							| 162 |  | fznn | ⊢ ( ( 𝑁  −  1 )  ∈  ℤ  →  ( ( 2nd  ‘ 𝑥 )  ∈  ( 1 ... ( 𝑁  −  1 ) )  ↔  ( ( 2nd  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) ) | 
						
							| 163 | 161 162 | syl | ⊢ ( 𝜑  →  ( ( 2nd  ‘ 𝑥 )  ∈  ( 1 ... ( 𝑁  −  1 ) )  ↔  ( ( 2nd  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) ) | 
						
							| 164 | 160 163 | anbi12d | ⊢ ( 𝜑  →  ( ( ( 1st  ‘ 𝑥 )  ∈  ( 1 ... ( 𝑀  −  1 ) )  ∧  ( 2nd  ‘ 𝑥 )  ∈  ( 1 ... ( 𝑁  −  1 ) ) )  ↔  ( ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) )  ∧  ( ( 2nd  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) ) ) | 
						
							| 165 |  | an4 | ⊢ ( ( ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 ) )  ∧  ( ( 2nd  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) )  ↔  ( ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ )  ∧  ( ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 )  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) ) | 
						
							| 166 | 164 165 | bitrdi | ⊢ ( 𝜑  →  ( ( ( 1st  ‘ 𝑥 )  ∈  ( 1 ... ( 𝑀  −  1 ) )  ∧  ( 2nd  ‘ 𝑥 )  ∈  ( 1 ... ( 𝑁  −  1 ) ) )  ↔  ( ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ )  ∧  ( ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 )  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) ) ) | 
						
							| 167 | 166 | adantr | ⊢ ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  →  ( ( ( 1st  ‘ 𝑥 )  ∈  ( 1 ... ( 𝑀  −  1 ) )  ∧  ( 2nd  ‘ 𝑥 )  ∈  ( 1 ... ( 𝑁  −  1 ) ) )  ↔  ( ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ )  ∧  ( ( 1st  ‘ 𝑥 )  ≤  ( 𝑀  −  1 )  ∧  ( 2nd  ‘ 𝑥 )  ≤  ( 𝑁  −  1 ) ) ) ) ) | 
						
							| 168 | 156 167 | bitr4d | ⊢ ( ( 𝜑  ∧  𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉 )  →  ( ( ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ )  ∧  ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 𝑥 )  ∈  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) )  ↔  ( ( 1st  ‘ 𝑥 )  ∈  ( 1 ... ( 𝑀  −  1 ) )  ∧  ( 2nd  ‘ 𝑥 )  ∈  ( 1 ... ( 𝑁  −  1 ) ) ) ) ) | 
						
							| 169 | 168 | pm5.32da | ⊢ ( 𝜑  →  ( ( 𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉  ∧  ( ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ )  ∧  ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 𝑥 )  ∈  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) ) )  ↔  ( 𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ( 1 ... ( 𝑀  −  1 ) )  ∧  ( 2nd  ‘ 𝑥 )  ∈  ( 1 ... ( 𝑁  −  1 ) ) ) ) ) ) | 
						
							| 170 |  | elxp6 | ⊢ ( 𝑥  ∈  ( ℕ  ×  ℕ )  ↔  ( 𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) ) ) | 
						
							| 171 | 170 | anbi1i | ⊢ ( ( 𝑥  ∈  ( ℕ  ×  ℕ )  ∧  ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 𝑥 )  ∈  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) )  ↔  ( ( 𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 𝑥 )  ∈  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) ) ) | 
						
							| 172 |  | anass | ⊢ ( ( ( 𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ ) )  ∧  ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 𝑥 )  ∈  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) )  ↔  ( 𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉  ∧  ( ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ )  ∧  ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 𝑥 )  ∈  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) ) ) ) | 
						
							| 173 | 171 172 | bitri | ⊢ ( ( 𝑥  ∈  ( ℕ  ×  ℕ )  ∧  ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 𝑥 )  ∈  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) )  ↔  ( 𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉  ∧  ( ( ( 1st  ‘ 𝑥 )  ∈  ℕ  ∧  ( 2nd  ‘ 𝑥 )  ∈  ℕ )  ∧  ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 𝑥 )  ∈  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) ) ) ) | 
						
							| 174 |  | elxp6 | ⊢ ( 𝑥  ∈  ( ( 1 ... ( 𝑀  −  1 ) )  ×  ( 1 ... ( 𝑁  −  1 ) ) )  ↔  ( 𝑥  =  〈 ( 1st  ‘ 𝑥 ) ,  ( 2nd  ‘ 𝑥 ) 〉  ∧  ( ( 1st  ‘ 𝑥 )  ∈  ( 1 ... ( 𝑀  −  1 ) )  ∧  ( 2nd  ‘ 𝑥 )  ∈  ( 1 ... ( 𝑁  −  1 ) ) ) ) ) | 
						
							| 175 | 169 173 174 | 3bitr4g | ⊢ ( 𝜑  →  ( ( 𝑥  ∈  ( ℕ  ×  ℕ )  ∧  ( ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ‘ 𝑥 )  ∈  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) )  ↔  𝑥  ∈  ( ( 1 ... ( 𝑀  −  1 ) )  ×  ( 1 ... ( 𝑁  −  1 ) ) ) ) ) | 
						
							| 176 | 31 36 175 | 3bitrd | ⊢ ( 𝜑  →  ( 𝑥  ∈  ( ◡ ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 )  “  dom  𝐴 )  ↔  𝑥  ∈  ( ( 1 ... ( 𝑀  −  1 ) )  ×  ( 1 ... ( 𝑁  −  1 ) ) ) ) ) | 
						
							| 177 | 176 | eqrdv | ⊢ ( 𝜑  →  ( ◡ ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 )  “  dom  𝐴 )  =  ( ( 1 ... ( 𝑀  −  1 ) )  ×  ( 1 ... ( 𝑁  −  1 ) ) ) ) | 
						
							| 178 | 27 177 | eqtrid | ⊢ ( 𝜑  →  dom  ( 𝐴  ∘  ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) )  =  ( ( 1 ... ( 𝑀  −  1 ) )  ×  ( 1 ... ( 𝑁  −  1 ) ) ) ) | 
						
							| 179 | 26 178 | eqtrd | ⊢ ( 𝜑  →  dom  𝑆  =  ( ( 1 ... ( 𝑀  −  1 ) )  ×  ( 1 ... ( 𝑁  −  1 ) ) ) ) | 
						
							| 180 | 179 | feq2d | ⊢ ( 𝜑  →  ( 𝑆 : dom  𝑆 ⟶ ran  𝑆  ↔  𝑆 : ( ( 1 ... ( 𝑀  −  1 ) )  ×  ( 1 ... ( 𝑁  −  1 ) ) ) ⟶ ran  𝑆 ) ) | 
						
							| 181 | 25 180 | mpbid | ⊢ ( 𝜑  →  𝑆 : ( ( 1 ... ( 𝑀  −  1 ) )  ×  ( 1 ... ( 𝑁  −  1 ) ) ) ⟶ ran  𝑆 ) | 
						
							| 182 | 21 | rneqd | ⊢ ( 𝜑  →  ran  𝑆  =  ran  ( 𝐴  ∘  ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) ) ) | 
						
							| 183 |  | rncoss | ⊢ ran  ( 𝐴  ∘  ( 𝑖  ∈  ℕ ,  𝑗  ∈  ℕ  ↦  〈 if ( 𝑖  <  𝐾 ,  𝑖 ,  ( 𝑖  +  1 ) ) ,  if ( 𝑗  <  𝐿 ,  𝑗 ,  ( 𝑗  +  1 ) ) 〉 ) )  ⊆  ran  𝐴 | 
						
							| 184 | 182 183 | eqsstrdi | ⊢ ( 𝜑  →  ran  𝑆  ⊆  ran  𝐴 ) | 
						
							| 185 |  | frn | ⊢ ( 𝐴 : ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) ⟶ 𝐵  →  ran  𝐴  ⊆  𝐵 ) | 
						
							| 186 | 6 7 185 | 3syl | ⊢ ( 𝜑  →  ran  𝐴  ⊆  𝐵 ) | 
						
							| 187 | 184 186 | sstrd | ⊢ ( 𝜑  →  ran  𝑆  ⊆  𝐵 ) | 
						
							| 188 |  | fss | ⊢ ( ( 𝑆 : ( ( 1 ... ( 𝑀  −  1 ) )  ×  ( 1 ... ( 𝑁  −  1 ) ) ) ⟶ ran  𝑆  ∧  ran  𝑆  ⊆  𝐵 )  →  𝑆 : ( ( 1 ... ( 𝑀  −  1 ) )  ×  ( 1 ... ( 𝑁  −  1 ) ) ) ⟶ 𝐵 ) | 
						
							| 189 | 181 187 188 | syl2anc | ⊢ ( 𝜑  →  𝑆 : ( ( 1 ... ( 𝑀  −  1 ) )  ×  ( 1 ... ( 𝑁  −  1 ) ) ) ⟶ 𝐵 ) | 
						
							| 190 |  | reldmmap | ⊢ Rel  dom   ↑m | 
						
							| 191 | 190 | ovrcl | ⊢ ( 𝐴  ∈  ( 𝐵  ↑m  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) ) )  →  ( 𝐵  ∈  V  ∧  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) )  ∈  V ) ) | 
						
							| 192 | 6 191 | syl | ⊢ ( 𝜑  →  ( 𝐵  ∈  V  ∧  ( ( 1 ... 𝑀 )  ×  ( 1 ... 𝑁 ) )  ∈  V ) ) | 
						
							| 193 | 192 | simpld | ⊢ ( 𝜑  →  𝐵  ∈  V ) | 
						
							| 194 |  | ovex | ⊢ ( 1 ... ( 𝑀  −  1 ) )  ∈  V | 
						
							| 195 |  | ovex | ⊢ ( 1 ... ( 𝑁  −  1 ) )  ∈  V | 
						
							| 196 | 194 195 | xpex | ⊢ ( ( 1 ... ( 𝑀  −  1 ) )  ×  ( 1 ... ( 𝑁  −  1 ) ) )  ∈  V | 
						
							| 197 |  | elmapg | ⊢ ( ( 𝐵  ∈  V  ∧  ( ( 1 ... ( 𝑀  −  1 ) )  ×  ( 1 ... ( 𝑁  −  1 ) ) )  ∈  V )  →  ( 𝑆  ∈  ( 𝐵  ↑m  ( ( 1 ... ( 𝑀  −  1 ) )  ×  ( 1 ... ( 𝑁  −  1 ) ) ) )  ↔  𝑆 : ( ( 1 ... ( 𝑀  −  1 ) )  ×  ( 1 ... ( 𝑁  −  1 ) ) ) ⟶ 𝐵 ) ) | 
						
							| 198 | 193 196 197 | sylancl | ⊢ ( 𝜑  →  ( 𝑆  ∈  ( 𝐵  ↑m  ( ( 1 ... ( 𝑀  −  1 ) )  ×  ( 1 ... ( 𝑁  −  1 ) ) ) )  ↔  𝑆 : ( ( 1 ... ( 𝑀  −  1 ) )  ×  ( 1 ... ( 𝑁  −  1 ) ) ) ⟶ 𝐵 ) ) | 
						
							| 199 | 189 198 | mpbird | ⊢ ( 𝜑  →  𝑆  ∈  ( 𝐵  ↑m  ( ( 1 ... ( 𝑀  −  1 ) )  ×  ( 1 ... ( 𝑁  −  1 ) ) ) ) ) |