| Step | Hyp | Ref | Expression | 
						
							| 1 |  | lmatfval.m | ⊢ 𝑀  =  ( litMat ‘ 𝑊 ) | 
						
							| 2 |  | lmatfval.n | ⊢ ( 𝜑  →  𝑁  ∈  ℕ ) | 
						
							| 3 |  | lmatfval.w | ⊢ ( 𝜑  →  𝑊  ∈  Word  Word  𝑉 ) | 
						
							| 4 |  | lmatfval.1 | ⊢ ( 𝜑  →  ( ♯ ‘ 𝑊 )  =  𝑁 ) | 
						
							| 5 |  | lmatfval.2 | ⊢ ( ( 𝜑  ∧  𝑖  ∈  ( 0 ..^ 𝑁 ) )  →  ( ♯ ‘ ( 𝑊 ‘ 𝑖 ) )  =  𝑁 ) | 
						
							| 6 |  | lmatfval.i | ⊢ ( 𝜑  →  𝐼  ∈  ( 1 ... 𝑁 ) ) | 
						
							| 7 |  | lmatfval.j | ⊢ ( 𝜑  →  𝐽  ∈  ( 1 ... 𝑁 ) ) | 
						
							| 8 |  | lmatval | ⊢ ( 𝑊  ∈  Word  Word  𝑉  →  ( litMat ‘ 𝑊 )  =  ( 𝑖  ∈  ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑗  ∈  ( 1 ... ( ♯ ‘ ( 𝑊 ‘ 0 ) ) )  ↦  ( ( 𝑊 ‘ ( 𝑖  −  1 ) ) ‘ ( 𝑗  −  1 ) ) ) ) | 
						
							| 9 | 3 8 | syl | ⊢ ( 𝜑  →  ( litMat ‘ 𝑊 )  =  ( 𝑖  ∈  ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑗  ∈  ( 1 ... ( ♯ ‘ ( 𝑊 ‘ 0 ) ) )  ↦  ( ( 𝑊 ‘ ( 𝑖  −  1 ) ) ‘ ( 𝑗  −  1 ) ) ) ) | 
						
							| 10 | 1 9 | eqtrid | ⊢ ( 𝜑  →  𝑀  =  ( 𝑖  ∈  ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑗  ∈  ( 1 ... ( ♯ ‘ ( 𝑊 ‘ 0 ) ) )  ↦  ( ( 𝑊 ‘ ( 𝑖  −  1 ) ) ‘ ( 𝑗  −  1 ) ) ) ) | 
						
							| 11 |  | simprl | ⊢ ( ( 𝜑  ∧  ( 𝑖  =  𝐼  ∧  𝑗  =  𝐽 ) )  →  𝑖  =  𝐼 ) | 
						
							| 12 | 11 | fvoveq1d | ⊢ ( ( 𝜑  ∧  ( 𝑖  =  𝐼  ∧  𝑗  =  𝐽 ) )  →  ( 𝑊 ‘ ( 𝑖  −  1 ) )  =  ( 𝑊 ‘ ( 𝐼  −  1 ) ) ) | 
						
							| 13 |  | simprr | ⊢ ( ( 𝜑  ∧  ( 𝑖  =  𝐼  ∧  𝑗  =  𝐽 ) )  →  𝑗  =  𝐽 ) | 
						
							| 14 | 13 | oveq1d | ⊢ ( ( 𝜑  ∧  ( 𝑖  =  𝐼  ∧  𝑗  =  𝐽 ) )  →  ( 𝑗  −  1 )  =  ( 𝐽  −  1 ) ) | 
						
							| 15 | 12 14 | fveq12d | ⊢ ( ( 𝜑  ∧  ( 𝑖  =  𝐼  ∧  𝑗  =  𝐽 ) )  →  ( ( 𝑊 ‘ ( 𝑖  −  1 ) ) ‘ ( 𝑗  −  1 ) )  =  ( ( 𝑊 ‘ ( 𝐼  −  1 ) ) ‘ ( 𝐽  −  1 ) ) ) | 
						
							| 16 | 4 | oveq2d | ⊢ ( 𝜑  →  ( 1 ... ( ♯ ‘ 𝑊 ) )  =  ( 1 ... 𝑁 ) ) | 
						
							| 17 | 6 16 | eleqtrrd | ⊢ ( 𝜑  →  𝐼  ∈  ( 1 ... ( ♯ ‘ 𝑊 ) ) ) | 
						
							| 18 |  | 1m1e0 | ⊢ ( 1  −  1 )  =  0 | 
						
							| 19 |  | nnuz | ⊢ ℕ  =  ( ℤ≥ ‘ 1 ) | 
						
							| 20 | 2 19 | eleqtrdi | ⊢ ( 𝜑  →  𝑁  ∈  ( ℤ≥ ‘ 1 ) ) | 
						
							| 21 |  | eluzfz1 | ⊢ ( 𝑁  ∈  ( ℤ≥ ‘ 1 )  →  1  ∈  ( 1 ... 𝑁 ) ) | 
						
							| 22 | 20 21 | syl | ⊢ ( 𝜑  →  1  ∈  ( 1 ... 𝑁 ) ) | 
						
							| 23 |  | fz1fzo0m1 | ⊢ ( 1  ∈  ( 1 ... 𝑁 )  →  ( 1  −  1 )  ∈  ( 0 ..^ 𝑁 ) ) | 
						
							| 24 | 22 23 | syl | ⊢ ( 𝜑  →  ( 1  −  1 )  ∈  ( 0 ..^ 𝑁 ) ) | 
						
							| 25 | 18 24 | eqeltrrid | ⊢ ( 𝜑  →  0  ∈  ( 0 ..^ 𝑁 ) ) | 
						
							| 26 |  | simpr | ⊢ ( ( 𝜑  ∧  𝑖  =  0 )  →  𝑖  =  0 ) | 
						
							| 27 | 26 | eleq1d | ⊢ ( ( 𝜑  ∧  𝑖  =  0 )  →  ( 𝑖  ∈  ( 0 ..^ 𝑁 )  ↔  0  ∈  ( 0 ..^ 𝑁 ) ) ) | 
						
							| 28 | 26 | fveq2d | ⊢ ( ( 𝜑  ∧  𝑖  =  0 )  →  ( 𝑊 ‘ 𝑖 )  =  ( 𝑊 ‘ 0 ) ) | 
						
							| 29 | 28 | fveqeq2d | ⊢ ( ( 𝜑  ∧  𝑖  =  0 )  →  ( ( ♯ ‘ ( 𝑊 ‘ 𝑖 ) )  =  𝑁  ↔  ( ♯ ‘ ( 𝑊 ‘ 0 ) )  =  𝑁 ) ) | 
						
							| 30 | 27 29 | imbi12d | ⊢ ( ( 𝜑  ∧  𝑖  =  0 )  →  ( ( 𝑖  ∈  ( 0 ..^ 𝑁 )  →  ( ♯ ‘ ( 𝑊 ‘ 𝑖 ) )  =  𝑁 )  ↔  ( 0  ∈  ( 0 ..^ 𝑁 )  →  ( ♯ ‘ ( 𝑊 ‘ 0 ) )  =  𝑁 ) ) ) | 
						
							| 31 | 5 | ex | ⊢ ( 𝜑  →  ( 𝑖  ∈  ( 0 ..^ 𝑁 )  →  ( ♯ ‘ ( 𝑊 ‘ 𝑖 ) )  =  𝑁 ) ) | 
						
							| 32 | 25 30 31 | vtocld | ⊢ ( 𝜑  →  ( 0  ∈  ( 0 ..^ 𝑁 )  →  ( ♯ ‘ ( 𝑊 ‘ 0 ) )  =  𝑁 ) ) | 
						
							| 33 | 25 32 | mpd | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝑊 ‘ 0 ) )  =  𝑁 ) | 
						
							| 34 | 33 | oveq2d | ⊢ ( 𝜑  →  ( 1 ... ( ♯ ‘ ( 𝑊 ‘ 0 ) ) )  =  ( 1 ... 𝑁 ) ) | 
						
							| 35 | 7 34 | eleqtrrd | ⊢ ( 𝜑  →  𝐽  ∈  ( 1 ... ( ♯ ‘ ( 𝑊 ‘ 0 ) ) ) ) | 
						
							| 36 |  | fz1fzo0m1 | ⊢ ( 𝐼  ∈  ( 1 ... 𝑁 )  →  ( 𝐼  −  1 )  ∈  ( 0 ..^ 𝑁 ) ) | 
						
							| 37 | 6 36 | syl | ⊢ ( 𝜑  →  ( 𝐼  −  1 )  ∈  ( 0 ..^ 𝑁 ) ) | 
						
							| 38 | 4 | oveq2d | ⊢ ( 𝜑  →  ( 0 ..^ ( ♯ ‘ 𝑊 ) )  =  ( 0 ..^ 𝑁 ) ) | 
						
							| 39 | 37 38 | eleqtrrd | ⊢ ( 𝜑  →  ( 𝐼  −  1 )  ∈  ( 0 ..^ ( ♯ ‘ 𝑊 ) ) ) | 
						
							| 40 |  | wrdsymbcl | ⊢ ( ( 𝑊  ∈  Word  Word  𝑉  ∧  ( 𝐼  −  1 )  ∈  ( 0 ..^ ( ♯ ‘ 𝑊 ) ) )  →  ( 𝑊 ‘ ( 𝐼  −  1 ) )  ∈  Word  𝑉 ) | 
						
							| 41 | 3 39 40 | syl2anc | ⊢ ( 𝜑  →  ( 𝑊 ‘ ( 𝐼  −  1 ) )  ∈  Word  𝑉 ) | 
						
							| 42 |  | fz1fzo0m1 | ⊢ ( 𝐽  ∈  ( 1 ... 𝑁 )  →  ( 𝐽  −  1 )  ∈  ( 0 ..^ 𝑁 ) ) | 
						
							| 43 | 7 42 | syl | ⊢ ( 𝜑  →  ( 𝐽  −  1 )  ∈  ( 0 ..^ 𝑁 ) ) | 
						
							| 44 |  | simpr | ⊢ ( ( 𝜑  ∧  𝑖  =  ( 𝐼  −  1 ) )  →  𝑖  =  ( 𝐼  −  1 ) ) | 
						
							| 45 | 44 | eleq1d | ⊢ ( ( 𝜑  ∧  𝑖  =  ( 𝐼  −  1 ) )  →  ( 𝑖  ∈  ( 0 ..^ 𝑁 )  ↔  ( 𝐼  −  1 )  ∈  ( 0 ..^ 𝑁 ) ) ) | 
						
							| 46 | 44 | fveq2d | ⊢ ( ( 𝜑  ∧  𝑖  =  ( 𝐼  −  1 ) )  →  ( 𝑊 ‘ 𝑖 )  =  ( 𝑊 ‘ ( 𝐼  −  1 ) ) ) | 
						
							| 47 | 46 | fveqeq2d | ⊢ ( ( 𝜑  ∧  𝑖  =  ( 𝐼  −  1 ) )  →  ( ( ♯ ‘ ( 𝑊 ‘ 𝑖 ) )  =  𝑁  ↔  ( ♯ ‘ ( 𝑊 ‘ ( 𝐼  −  1 ) ) )  =  𝑁 ) ) | 
						
							| 48 | 45 47 | imbi12d | ⊢ ( ( 𝜑  ∧  𝑖  =  ( 𝐼  −  1 ) )  →  ( ( 𝑖  ∈  ( 0 ..^ 𝑁 )  →  ( ♯ ‘ ( 𝑊 ‘ 𝑖 ) )  =  𝑁 )  ↔  ( ( 𝐼  −  1 )  ∈  ( 0 ..^ 𝑁 )  →  ( ♯ ‘ ( 𝑊 ‘ ( 𝐼  −  1 ) ) )  =  𝑁 ) ) ) | 
						
							| 49 | 37 48 31 | vtocld | ⊢ ( 𝜑  →  ( ( 𝐼  −  1 )  ∈  ( 0 ..^ 𝑁 )  →  ( ♯ ‘ ( 𝑊 ‘ ( 𝐼  −  1 ) ) )  =  𝑁 ) ) | 
						
							| 50 | 37 49 | mpd | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝑊 ‘ ( 𝐼  −  1 ) ) )  =  𝑁 ) | 
						
							| 51 | 50 | oveq2d | ⊢ ( 𝜑  →  ( 0 ..^ ( ♯ ‘ ( 𝑊 ‘ ( 𝐼  −  1 ) ) ) )  =  ( 0 ..^ 𝑁 ) ) | 
						
							| 52 | 43 51 | eleqtrrd | ⊢ ( 𝜑  →  ( 𝐽  −  1 )  ∈  ( 0 ..^ ( ♯ ‘ ( 𝑊 ‘ ( 𝐼  −  1 ) ) ) ) ) | 
						
							| 53 |  | wrdsymbcl | ⊢ ( ( ( 𝑊 ‘ ( 𝐼  −  1 ) )  ∈  Word  𝑉  ∧  ( 𝐽  −  1 )  ∈  ( 0 ..^ ( ♯ ‘ ( 𝑊 ‘ ( 𝐼  −  1 ) ) ) ) )  →  ( ( 𝑊 ‘ ( 𝐼  −  1 ) ) ‘ ( 𝐽  −  1 ) )  ∈  𝑉 ) | 
						
							| 54 | 41 52 53 | syl2anc | ⊢ ( 𝜑  →  ( ( 𝑊 ‘ ( 𝐼  −  1 ) ) ‘ ( 𝐽  −  1 ) )  ∈  𝑉 ) | 
						
							| 55 | 10 15 17 35 54 | ovmpod | ⊢ ( 𝜑  →  ( 𝐼 𝑀 𝐽 )  =  ( ( 𝑊 ‘ ( 𝐼  −  1 ) ) ‘ ( 𝐽  −  1 ) ) ) |