| Step | Hyp | Ref | Expression | 
						
							| 1 |  | efgval.w | ⊢ 𝑊  =  (  I  ‘ Word  ( 𝐼  ×  2o ) ) | 
						
							| 2 |  | efgval.r | ⊢  ∼   =  (  ~FG  ‘ 𝐼 ) | 
						
							| 3 |  | efgval2.m | ⊢ 𝑀  =  ( 𝑦  ∈  𝐼 ,  𝑧  ∈  2o  ↦  〈 𝑦 ,  ( 1o  ∖  𝑧 ) 〉 ) | 
						
							| 4 |  | efgval2.t | ⊢ 𝑇  =  ( 𝑣  ∈  𝑊  ↦  ( 𝑛  ∈  ( 0 ... ( ♯ ‘ 𝑣 ) ) ,  𝑤  ∈  ( 𝐼  ×  2o )  ↦  ( 𝑣  splice  〈 𝑛 ,  𝑛 ,  〈“ 𝑤 ( 𝑀 ‘ 𝑤 ) ”〉 〉 ) ) ) | 
						
							| 5 |  | efgred.d | ⊢ 𝐷  =  ( 𝑊  ∖  ∪  𝑥  ∈  𝑊 ran  ( 𝑇 ‘ 𝑥 ) ) | 
						
							| 6 |  | efgred.s | ⊢ 𝑆  =  ( 𝑚  ∈  { 𝑡  ∈  ( Word  𝑊  ∖  { ∅ } )  ∣  ( ( 𝑡 ‘ 0 )  ∈  𝐷  ∧  ∀ 𝑘  ∈  ( 1 ..^ ( ♯ ‘ 𝑡 ) ) ( 𝑡 ‘ 𝑘 )  ∈  ran  ( 𝑇 ‘ ( 𝑡 ‘ ( 𝑘  −  1 ) ) ) ) }  ↦  ( 𝑚 ‘ ( ( ♯ ‘ 𝑚 )  −  1 ) ) ) | 
						
							| 7 |  | efgredlem.1 | ⊢ ( 𝜑  →  ∀ 𝑎  ∈  dom  𝑆 ∀ 𝑏  ∈  dom  𝑆 ( ( ♯ ‘ ( 𝑆 ‘ 𝑎 ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  →  ( ( 𝑆 ‘ 𝑎 )  =  ( 𝑆 ‘ 𝑏 )  →  ( 𝑎 ‘ 0 )  =  ( 𝑏 ‘ 0 ) ) ) ) | 
						
							| 8 |  | efgredlem.2 | ⊢ ( 𝜑  →  𝐴  ∈  dom  𝑆 ) | 
						
							| 9 |  | efgredlem.3 | ⊢ ( 𝜑  →  𝐵  ∈  dom  𝑆 ) | 
						
							| 10 |  | efgredlem.4 | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝐴 )  =  ( 𝑆 ‘ 𝐵 ) ) | 
						
							| 11 |  | efgredlem.5 | ⊢ ( 𝜑  →  ¬  ( 𝐴 ‘ 0 )  =  ( 𝐵 ‘ 0 ) ) | 
						
							| 12 |  | efgredlemb.k | ⊢ 𝐾  =  ( ( ( ♯ ‘ 𝐴 )  −  1 )  −  1 ) | 
						
							| 13 |  | efgredlemb.l | ⊢ 𝐿  =  ( ( ( ♯ ‘ 𝐵 )  −  1 )  −  1 ) | 
						
							| 14 |  | efgredlemb.p | ⊢ ( 𝜑  →  𝑃  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) ) ) | 
						
							| 15 |  | efgredlemb.q | ⊢ ( 𝜑  →  𝑄  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) ) ) | 
						
							| 16 |  | efgredlemb.u | ⊢ ( 𝜑  →  𝑈  ∈  ( 𝐼  ×  2o ) ) | 
						
							| 17 |  | efgredlemb.v | ⊢ ( 𝜑  →  𝑉  ∈  ( 𝐼  ×  2o ) ) | 
						
							| 18 |  | efgredlemb.6 | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝐴 )  =  ( 𝑃 ( 𝑇 ‘ ( 𝐴 ‘ 𝐾 ) ) 𝑈 ) ) | 
						
							| 19 |  | efgredlemb.7 | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝐵 )  =  ( 𝑄 ( 𝑇 ‘ ( 𝐵 ‘ 𝐿 ) ) 𝑉 ) ) | 
						
							| 20 |  | efgredlemb.8 | ⊢ ( 𝜑  →  ¬  ( 𝐴 ‘ 𝐾 )  =  ( 𝐵 ‘ 𝐿 ) ) | 
						
							| 21 |  | efgredlemd.9 | ⊢ ( 𝜑  →  𝑃  ∈  ( ℤ≥ ‘ ( 𝑄  +  2 ) ) ) | 
						
							| 22 |  | efgredlemd.c | ⊢ ( 𝜑  →  𝐶  ∈  dom  𝑆 ) | 
						
							| 23 |  | efgredlemd.sc | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝐶 )  =  ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) | 
						
							| 24 | 1 2 3 4 5 6 | efgsdm | ⊢ ( 𝐶  ∈  dom  𝑆  ↔  ( 𝐶  ∈  ( Word  𝑊  ∖  { ∅ } )  ∧  ( 𝐶 ‘ 0 )  ∈  𝐷  ∧  ∀ 𝑖  ∈  ( 1 ..^ ( ♯ ‘ 𝐶 ) ) ( 𝐶 ‘ 𝑖 )  ∈  ran  ( 𝑇 ‘ ( 𝐶 ‘ ( 𝑖  −  1 ) ) ) ) ) | 
						
							| 25 | 24 | simp1bi | ⊢ ( 𝐶  ∈  dom  𝑆  →  𝐶  ∈  ( Word  𝑊  ∖  { ∅ } ) ) | 
						
							| 26 | 22 25 | syl | ⊢ ( 𝜑  →  𝐶  ∈  ( Word  𝑊  ∖  { ∅ } ) ) | 
						
							| 27 | 26 | eldifad | ⊢ ( 𝜑  →  𝐶  ∈  Word  𝑊 ) | 
						
							| 28 | 1 2 3 4 5 6 | efgsdm | ⊢ ( 𝐴  ∈  dom  𝑆  ↔  ( 𝐴  ∈  ( Word  𝑊  ∖  { ∅ } )  ∧  ( 𝐴 ‘ 0 )  ∈  𝐷  ∧  ∀ 𝑖  ∈  ( 1 ..^ ( ♯ ‘ 𝐴 ) ) ( 𝐴 ‘ 𝑖 )  ∈  ran  ( 𝑇 ‘ ( 𝐴 ‘ ( 𝑖  −  1 ) ) ) ) ) | 
						
							| 29 | 28 | simp1bi | ⊢ ( 𝐴  ∈  dom  𝑆  →  𝐴  ∈  ( Word  𝑊  ∖  { ∅ } ) ) | 
						
							| 30 | 8 29 | syl | ⊢ ( 𝜑  →  𝐴  ∈  ( Word  𝑊  ∖  { ∅ } ) ) | 
						
							| 31 | 30 | eldifad | ⊢ ( 𝜑  →  𝐴  ∈  Word  𝑊 ) | 
						
							| 32 |  | wrdf | ⊢ ( 𝐴  ∈  Word  𝑊  →  𝐴 : ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ⟶ 𝑊 ) | 
						
							| 33 | 31 32 | syl | ⊢ ( 𝜑  →  𝐴 : ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ⟶ 𝑊 ) | 
						
							| 34 |  | fzossfz | ⊢ ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) )  ⊆  ( 0 ... ( ( ♯ ‘ 𝐴 )  −  1 ) ) | 
						
							| 35 |  | lencl | ⊢ ( 𝐴  ∈  Word  𝑊  →  ( ♯ ‘ 𝐴 )  ∈  ℕ0 ) | 
						
							| 36 | 31 35 | syl | ⊢ ( 𝜑  →  ( ♯ ‘ 𝐴 )  ∈  ℕ0 ) | 
						
							| 37 | 36 | nn0zd | ⊢ ( 𝜑  →  ( ♯ ‘ 𝐴 )  ∈  ℤ ) | 
						
							| 38 |  | fzoval | ⊢ ( ( ♯ ‘ 𝐴 )  ∈  ℤ  →  ( 0 ..^ ( ♯ ‘ 𝐴 ) )  =  ( 0 ... ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) | 
						
							| 39 | 37 38 | syl | ⊢ ( 𝜑  →  ( 0 ..^ ( ♯ ‘ 𝐴 ) )  =  ( 0 ... ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) | 
						
							| 40 | 34 39 | sseqtrrid | ⊢ ( 𝜑  →  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) )  ⊆  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ) | 
						
							| 41 | 1 2 3 4 5 6 7 8 9 10 11 | efgredlema | ⊢ ( 𝜑  →  ( ( ( ♯ ‘ 𝐴 )  −  1 )  ∈  ℕ  ∧  ( ( ♯ ‘ 𝐵 )  −  1 )  ∈  ℕ ) ) | 
						
							| 42 | 41 | simpld | ⊢ ( 𝜑  →  ( ( ♯ ‘ 𝐴 )  −  1 )  ∈  ℕ ) | 
						
							| 43 |  | fzo0end | ⊢ ( ( ( ♯ ‘ 𝐴 )  −  1 )  ∈  ℕ  →  ( ( ( ♯ ‘ 𝐴 )  −  1 )  −  1 )  ∈  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) | 
						
							| 44 | 42 43 | syl | ⊢ ( 𝜑  →  ( ( ( ♯ ‘ 𝐴 )  −  1 )  −  1 )  ∈  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) | 
						
							| 45 | 12 44 | eqeltrid | ⊢ ( 𝜑  →  𝐾  ∈  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) | 
						
							| 46 | 40 45 | sseldd | ⊢ ( 𝜑  →  𝐾  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ) | 
						
							| 47 | 33 46 | ffvelcdmd | ⊢ ( 𝜑  →  ( 𝐴 ‘ 𝐾 )  ∈  𝑊 ) | 
						
							| 48 | 47 | s1cld | ⊢ ( 𝜑  →  〈“ ( 𝐴 ‘ 𝐾 ) ”〉  ∈  Word  𝑊 ) | 
						
							| 49 |  | eldifsn | ⊢ ( 𝐶  ∈  ( Word  𝑊  ∖  { ∅ } )  ↔  ( 𝐶  ∈  Word  𝑊  ∧  𝐶  ≠  ∅ ) ) | 
						
							| 50 |  | lennncl | ⊢ ( ( 𝐶  ∈  Word  𝑊  ∧  𝐶  ≠  ∅ )  →  ( ♯ ‘ 𝐶 )  ∈  ℕ ) | 
						
							| 51 | 49 50 | sylbi | ⊢ ( 𝐶  ∈  ( Word  𝑊  ∖  { ∅ } )  →  ( ♯ ‘ 𝐶 )  ∈  ℕ ) | 
						
							| 52 | 26 51 | syl | ⊢ ( 𝜑  →  ( ♯ ‘ 𝐶 )  ∈  ℕ ) | 
						
							| 53 |  | lbfzo0 | ⊢ ( 0  ∈  ( 0 ..^ ( ♯ ‘ 𝐶 ) )  ↔  ( ♯ ‘ 𝐶 )  ∈  ℕ ) | 
						
							| 54 | 52 53 | sylibr | ⊢ ( 𝜑  →  0  ∈  ( 0 ..^ ( ♯ ‘ 𝐶 ) ) ) | 
						
							| 55 |  | ccatval1 | ⊢ ( ( 𝐶  ∈  Word  𝑊  ∧  〈“ ( 𝐴 ‘ 𝐾 ) ”〉  ∈  Word  𝑊  ∧  0  ∈  ( 0 ..^ ( ♯ ‘ 𝐶 ) ) )  →  ( ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 ) ‘ 0 )  =  ( 𝐶 ‘ 0 ) ) | 
						
							| 56 | 27 48 54 55 | syl3anc | ⊢ ( 𝜑  →  ( ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 ) ‘ 0 )  =  ( 𝐶 ‘ 0 ) ) | 
						
							| 57 | 1 2 3 4 5 6 | efgsdm | ⊢ ( 𝐵  ∈  dom  𝑆  ↔  ( 𝐵  ∈  ( Word  𝑊  ∖  { ∅ } )  ∧  ( 𝐵 ‘ 0 )  ∈  𝐷  ∧  ∀ 𝑖  ∈  ( 1 ..^ ( ♯ ‘ 𝐵 ) ) ( 𝐵 ‘ 𝑖 )  ∈  ran  ( 𝑇 ‘ ( 𝐵 ‘ ( 𝑖  −  1 ) ) ) ) ) | 
						
							| 58 | 57 | simp1bi | ⊢ ( 𝐵  ∈  dom  𝑆  →  𝐵  ∈  ( Word  𝑊  ∖  { ∅ } ) ) | 
						
							| 59 | 9 58 | syl | ⊢ ( 𝜑  →  𝐵  ∈  ( Word  𝑊  ∖  { ∅ } ) ) | 
						
							| 60 | 59 | eldifad | ⊢ ( 𝜑  →  𝐵  ∈  Word  𝑊 ) | 
						
							| 61 |  | wrdf | ⊢ ( 𝐵  ∈  Word  𝑊  →  𝐵 : ( 0 ..^ ( ♯ ‘ 𝐵 ) ) ⟶ 𝑊 ) | 
						
							| 62 | 60 61 | syl | ⊢ ( 𝜑  →  𝐵 : ( 0 ..^ ( ♯ ‘ 𝐵 ) ) ⟶ 𝑊 ) | 
						
							| 63 |  | fzossfz | ⊢ ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) )  ⊆  ( 0 ... ( ( ♯ ‘ 𝐵 )  −  1 ) ) | 
						
							| 64 |  | lencl | ⊢ ( 𝐵  ∈  Word  𝑊  →  ( ♯ ‘ 𝐵 )  ∈  ℕ0 ) | 
						
							| 65 | 60 64 | syl | ⊢ ( 𝜑  →  ( ♯ ‘ 𝐵 )  ∈  ℕ0 ) | 
						
							| 66 | 65 | nn0zd | ⊢ ( 𝜑  →  ( ♯ ‘ 𝐵 )  ∈  ℤ ) | 
						
							| 67 |  | fzoval | ⊢ ( ( ♯ ‘ 𝐵 )  ∈  ℤ  →  ( 0 ..^ ( ♯ ‘ 𝐵 ) )  =  ( 0 ... ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) | 
						
							| 68 | 66 67 | syl | ⊢ ( 𝜑  →  ( 0 ..^ ( ♯ ‘ 𝐵 ) )  =  ( 0 ... ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) | 
						
							| 69 | 63 68 | sseqtrrid | ⊢ ( 𝜑  →  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) )  ⊆  ( 0 ..^ ( ♯ ‘ 𝐵 ) ) ) | 
						
							| 70 | 41 | simprd | ⊢ ( 𝜑  →  ( ( ♯ ‘ 𝐵 )  −  1 )  ∈  ℕ ) | 
						
							| 71 |  | fzo0end | ⊢ ( ( ( ♯ ‘ 𝐵 )  −  1 )  ∈  ℕ  →  ( ( ( ♯ ‘ 𝐵 )  −  1 )  −  1 )  ∈  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) | 
						
							| 72 | 70 71 | syl | ⊢ ( 𝜑  →  ( ( ( ♯ ‘ 𝐵 )  −  1 )  −  1 )  ∈  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) | 
						
							| 73 | 13 72 | eqeltrid | ⊢ ( 𝜑  →  𝐿  ∈  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) | 
						
							| 74 | 69 73 | sseldd | ⊢ ( 𝜑  →  𝐿  ∈  ( 0 ..^ ( ♯ ‘ 𝐵 ) ) ) | 
						
							| 75 | 62 74 | ffvelcdmd | ⊢ ( 𝜑  →  ( 𝐵 ‘ 𝐿 )  ∈  𝑊 ) | 
						
							| 76 | 75 | s1cld | ⊢ ( 𝜑  →  〈“ ( 𝐵 ‘ 𝐿 ) ”〉  ∈  Word  𝑊 ) | 
						
							| 77 |  | ccatval1 | ⊢ ( ( 𝐶  ∈  Word  𝑊  ∧  〈“ ( 𝐵 ‘ 𝐿 ) ”〉  ∈  Word  𝑊  ∧  0  ∈  ( 0 ..^ ( ♯ ‘ 𝐶 ) ) )  →  ( ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 ) ‘ 0 )  =  ( 𝐶 ‘ 0 ) ) | 
						
							| 78 | 27 76 54 77 | syl3anc | ⊢ ( 𝜑  →  ( ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 ) ‘ 0 )  =  ( 𝐶 ‘ 0 ) ) | 
						
							| 79 | 56 78 | eqtr4d | ⊢ ( 𝜑  →  ( ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 ) ‘ 0 )  =  ( ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 ) ‘ 0 ) ) | 
						
							| 80 |  | fviss | ⊢ (  I  ‘ Word  ( 𝐼  ×  2o ) )  ⊆  Word  ( 𝐼  ×  2o ) | 
						
							| 81 | 1 80 | eqsstri | ⊢ 𝑊  ⊆  Word  ( 𝐼  ×  2o ) | 
						
							| 82 | 81 47 | sselid | ⊢ ( 𝜑  →  ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 83 |  | lencl | ⊢ ( ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ℕ0 ) | 
						
							| 84 | 82 83 | syl | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ℕ0 ) | 
						
							| 85 | 84 | nn0red | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ℝ ) | 
						
							| 86 |  | 2rp | ⊢ 2  ∈  ℝ+ | 
						
							| 87 |  | ltaddrp | ⊢ ( ( ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ℝ  ∧  2  ∈  ℝ+ )  →  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  <  ( ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  +  2 ) ) | 
						
							| 88 | 85 86 87 | sylancl | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  <  ( ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  +  2 ) ) | 
						
							| 89 | 36 | nn0red | ⊢ ( 𝜑  →  ( ♯ ‘ 𝐴 )  ∈  ℝ ) | 
						
							| 90 | 89 | lem1d | ⊢ ( 𝜑  →  ( ( ♯ ‘ 𝐴 )  −  1 )  ≤  ( ♯ ‘ 𝐴 ) ) | 
						
							| 91 |  | fznn | ⊢ ( ( ♯ ‘ 𝐴 )  ∈  ℤ  →  ( ( ( ♯ ‘ 𝐴 )  −  1 )  ∈  ( 1 ... ( ♯ ‘ 𝐴 ) )  ↔  ( ( ( ♯ ‘ 𝐴 )  −  1 )  ∈  ℕ  ∧  ( ( ♯ ‘ 𝐴 )  −  1 )  ≤  ( ♯ ‘ 𝐴 ) ) ) ) | 
						
							| 92 | 37 91 | syl | ⊢ ( 𝜑  →  ( ( ( ♯ ‘ 𝐴 )  −  1 )  ∈  ( 1 ... ( ♯ ‘ 𝐴 ) )  ↔  ( ( ( ♯ ‘ 𝐴 )  −  1 )  ∈  ℕ  ∧  ( ( ♯ ‘ 𝐴 )  −  1 )  ≤  ( ♯ ‘ 𝐴 ) ) ) ) | 
						
							| 93 | 42 90 92 | mpbir2and | ⊢ ( 𝜑  →  ( ( ♯ ‘ 𝐴 )  −  1 )  ∈  ( 1 ... ( ♯ ‘ 𝐴 ) ) ) | 
						
							| 94 | 1 2 3 4 5 6 | efgsres | ⊢ ( ( 𝐴  ∈  dom  𝑆  ∧  ( ( ♯ ‘ 𝐴 )  −  1 )  ∈  ( 1 ... ( ♯ ‘ 𝐴 ) ) )  →  ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) )  ∈  dom  𝑆 ) | 
						
							| 95 | 8 93 94 | syl2anc | ⊢ ( 𝜑  →  ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) )  ∈  dom  𝑆 ) | 
						
							| 96 | 1 2 3 4 5 6 | efgsval | ⊢ ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) )  ∈  dom  𝑆  →  ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  =  ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ ( ( ♯ ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  −  1 ) ) ) | 
						
							| 97 | 95 96 | syl | ⊢ ( 𝜑  →  ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  =  ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ ( ( ♯ ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  −  1 ) ) ) | 
						
							| 98 |  | fz1ssfz0 | ⊢ ( 1 ... ( ♯ ‘ 𝐴 ) )  ⊆  ( 0 ... ( ♯ ‘ 𝐴 ) ) | 
						
							| 99 | 98 93 | sselid | ⊢ ( 𝜑  →  ( ( ♯ ‘ 𝐴 )  −  1 )  ∈  ( 0 ... ( ♯ ‘ 𝐴 ) ) ) | 
						
							| 100 |  | pfxres | ⊢ ( ( 𝐴  ∈  Word  𝑊  ∧  ( ( ♯ ‘ 𝐴 )  −  1 )  ∈  ( 0 ... ( ♯ ‘ 𝐴 ) ) )  →  ( 𝐴  prefix  ( ( ♯ ‘ 𝐴 )  −  1 ) )  =  ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ) | 
						
							| 101 | 31 99 100 | syl2anc | ⊢ ( 𝜑  →  ( 𝐴  prefix  ( ( ♯ ‘ 𝐴 )  −  1 ) )  =  ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ) | 
						
							| 102 | 101 | fveq2d | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐴  prefix  ( ( ♯ ‘ 𝐴 )  −  1 ) ) )  =  ( ♯ ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ) ) | 
						
							| 103 |  | pfxlen | ⊢ ( ( 𝐴  ∈  Word  𝑊  ∧  ( ( ♯ ‘ 𝐴 )  −  1 )  ∈  ( 0 ... ( ♯ ‘ 𝐴 ) ) )  →  ( ♯ ‘ ( 𝐴  prefix  ( ( ♯ ‘ 𝐴 )  −  1 ) ) )  =  ( ( ♯ ‘ 𝐴 )  −  1 ) ) | 
						
							| 104 | 31 99 103 | syl2anc | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐴  prefix  ( ( ♯ ‘ 𝐴 )  −  1 ) ) )  =  ( ( ♯ ‘ 𝐴 )  −  1 ) ) | 
						
							| 105 | 102 104 | eqtr3d | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  =  ( ( ♯ ‘ 𝐴 )  −  1 ) ) | 
						
							| 106 | 105 | oveq1d | ⊢ ( 𝜑  →  ( ( ♯ ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  −  1 )  =  ( ( ( ♯ ‘ 𝐴 )  −  1 )  −  1 ) ) | 
						
							| 107 | 106 12 | eqtr4di | ⊢ ( 𝜑  →  ( ( ♯ ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  −  1 )  =  𝐾 ) | 
						
							| 108 | 107 | fveq2d | ⊢ ( 𝜑  →  ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ ( ( ♯ ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  −  1 ) )  =  ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ 𝐾 ) ) | 
						
							| 109 | 45 | fvresd | ⊢ ( 𝜑  →  ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ 𝐾 )  =  ( 𝐴 ‘ 𝐾 ) ) | 
						
							| 110 | 97 108 109 | 3eqtrd | ⊢ ( 𝜑  →  ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  =  ( 𝐴 ‘ 𝐾 ) ) | 
						
							| 111 | 110 | fveq2d | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ) )  =  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) ) | 
						
							| 112 | 1 2 3 4 5 6 | efgsdmi | ⊢ ( ( 𝐴  ∈  dom  𝑆  ∧  ( ( ♯ ‘ 𝐴 )  −  1 )  ∈  ℕ )  →  ( 𝑆 ‘ 𝐴 )  ∈  ran  ( 𝑇 ‘ ( 𝐴 ‘ ( ( ( ♯ ‘ 𝐴 )  −  1 )  −  1 ) ) ) ) | 
						
							| 113 | 8 42 112 | syl2anc | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝐴 )  ∈  ran  ( 𝑇 ‘ ( 𝐴 ‘ ( ( ( ♯ ‘ 𝐴 )  −  1 )  −  1 ) ) ) ) | 
						
							| 114 | 12 | fveq2i | ⊢ ( 𝐴 ‘ 𝐾 )  =  ( 𝐴 ‘ ( ( ( ♯ ‘ 𝐴 )  −  1 )  −  1 ) ) | 
						
							| 115 | 114 | fveq2i | ⊢ ( 𝑇 ‘ ( 𝐴 ‘ 𝐾 ) )  =  ( 𝑇 ‘ ( 𝐴 ‘ ( ( ( ♯ ‘ 𝐴 )  −  1 )  −  1 ) ) ) | 
						
							| 116 | 115 | rneqi | ⊢ ran  ( 𝑇 ‘ ( 𝐴 ‘ 𝐾 ) )  =  ran  ( 𝑇 ‘ ( 𝐴 ‘ ( ( ( ♯ ‘ 𝐴 )  −  1 )  −  1 ) ) ) | 
						
							| 117 | 113 116 | eleqtrrdi | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝐴 )  ∈  ran  ( 𝑇 ‘ ( 𝐴 ‘ 𝐾 ) ) ) | 
						
							| 118 | 1 2 3 4 | efgtlen | ⊢ ( ( ( 𝐴 ‘ 𝐾 )  ∈  𝑊  ∧  ( 𝑆 ‘ 𝐴 )  ∈  ran  ( 𝑇 ‘ ( 𝐴 ‘ 𝐾 ) ) )  →  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  =  ( ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  +  2 ) ) | 
						
							| 119 | 47 117 118 | syl2anc | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  =  ( ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  +  2 ) ) | 
						
							| 120 | 88 111 119 | 3brtr4d | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) ) ) | 
						
							| 121 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 | efgredleme | ⊢ ( 𝜑  →  ( ( 𝐴 ‘ 𝐾 )  ∈  ran  ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) )  ∧  ( 𝐵 ‘ 𝐿 )  ∈  ran  ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) ) ) | 
						
							| 122 | 121 | simpld | ⊢ ( 𝜑  →  ( 𝐴 ‘ 𝐾 )  ∈  ran  ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) ) | 
						
							| 123 | 1 2 3 4 5 6 | efgsp1 | ⊢ ( ( 𝐶  ∈  dom  𝑆  ∧  ( 𝐴 ‘ 𝐾 )  ∈  ran  ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) )  →  ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 )  ∈  dom  𝑆 ) | 
						
							| 124 | 22 122 123 | syl2anc | ⊢ ( 𝜑  →  ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 )  ∈  dom  𝑆 ) | 
						
							| 125 | 1 2 3 4 5 6 | efgsval2 | ⊢ ( ( 𝐶  ∈  Word  𝑊  ∧  ( 𝐴 ‘ 𝐾 )  ∈  𝑊  ∧  ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 )  ∈  dom  𝑆 )  →  ( 𝑆 ‘ ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 ) )  =  ( 𝐴 ‘ 𝐾 ) ) | 
						
							| 126 | 27 47 124 125 | syl3anc | ⊢ ( 𝜑  →  ( 𝑆 ‘ ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 ) )  =  ( 𝐴 ‘ 𝐾 ) ) | 
						
							| 127 | 110 126 | eqtr4d | ⊢ ( 𝜑  →  ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  =  ( 𝑆 ‘ ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 ) ) ) | 
						
							| 128 |  | 2fveq3 | ⊢ ( 𝑎  =  ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) )  →  ( ♯ ‘ ( 𝑆 ‘ 𝑎 ) )  =  ( ♯ ‘ ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ) ) ) | 
						
							| 129 | 128 | breq1d | ⊢ ( 𝑎  =  ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) )  →  ( ( ♯ ‘ ( 𝑆 ‘ 𝑎 ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  ↔  ( ♯ ‘ ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) ) ) ) | 
						
							| 130 |  | fveqeq2 | ⊢ ( 𝑎  =  ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) )  →  ( ( 𝑆 ‘ 𝑎 )  =  ( 𝑆 ‘ 𝑏 )  ↔  ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  =  ( 𝑆 ‘ 𝑏 ) ) ) | 
						
							| 131 |  | fveq1 | ⊢ ( 𝑎  =  ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) )  →  ( 𝑎 ‘ 0 )  =  ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ 0 ) ) | 
						
							| 132 | 131 | eqeq1d | ⊢ ( 𝑎  =  ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) )  →  ( ( 𝑎 ‘ 0 )  =  ( 𝑏 ‘ 0 )  ↔  ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ 0 )  =  ( 𝑏 ‘ 0 ) ) ) | 
						
							| 133 | 130 132 | imbi12d | ⊢ ( 𝑎  =  ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) )  →  ( ( ( 𝑆 ‘ 𝑎 )  =  ( 𝑆 ‘ 𝑏 )  →  ( 𝑎 ‘ 0 )  =  ( 𝑏 ‘ 0 ) )  ↔  ( ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  =  ( 𝑆 ‘ 𝑏 )  →  ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ 0 )  =  ( 𝑏 ‘ 0 ) ) ) ) | 
						
							| 134 | 129 133 | imbi12d | ⊢ ( 𝑎  =  ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) )  →  ( ( ( ♯ ‘ ( 𝑆 ‘ 𝑎 ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  →  ( ( 𝑆 ‘ 𝑎 )  =  ( 𝑆 ‘ 𝑏 )  →  ( 𝑎 ‘ 0 )  =  ( 𝑏 ‘ 0 ) ) )  ↔  ( ( ♯ ‘ ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  →  ( ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  =  ( 𝑆 ‘ 𝑏 )  →  ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ 0 )  =  ( 𝑏 ‘ 0 ) ) ) ) ) | 
						
							| 135 |  | fveq2 | ⊢ ( 𝑏  =  ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 )  →  ( 𝑆 ‘ 𝑏 )  =  ( 𝑆 ‘ ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 ) ) ) | 
						
							| 136 | 135 | eqeq2d | ⊢ ( 𝑏  =  ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 )  →  ( ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  =  ( 𝑆 ‘ 𝑏 )  ↔  ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  =  ( 𝑆 ‘ ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 ) ) ) ) | 
						
							| 137 |  | fveq1 | ⊢ ( 𝑏  =  ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 )  →  ( 𝑏 ‘ 0 )  =  ( ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 ) ‘ 0 ) ) | 
						
							| 138 | 137 | eqeq2d | ⊢ ( 𝑏  =  ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 )  →  ( ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ 0 )  =  ( 𝑏 ‘ 0 )  ↔  ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ 0 )  =  ( ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 ) ‘ 0 ) ) ) | 
						
							| 139 | 136 138 | imbi12d | ⊢ ( 𝑏  =  ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 )  →  ( ( ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  =  ( 𝑆 ‘ 𝑏 )  →  ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ 0 )  =  ( 𝑏 ‘ 0 ) )  ↔  ( ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  =  ( 𝑆 ‘ ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 ) )  →  ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ 0 )  =  ( ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 ) ‘ 0 ) ) ) ) | 
						
							| 140 | 139 | imbi2d | ⊢ ( 𝑏  =  ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 )  →  ( ( ( ♯ ‘ ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  →  ( ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  =  ( 𝑆 ‘ 𝑏 )  →  ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ 0 )  =  ( 𝑏 ‘ 0 ) ) )  ↔  ( ( ♯ ‘ ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  →  ( ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  =  ( 𝑆 ‘ ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 ) )  →  ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ 0 )  =  ( ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 ) ‘ 0 ) ) ) ) ) | 
						
							| 141 | 134 140 | rspc2va | ⊢ ( ( ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) )  ∈  dom  𝑆  ∧  ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 )  ∈  dom  𝑆 )  ∧  ∀ 𝑎  ∈  dom  𝑆 ∀ 𝑏  ∈  dom  𝑆 ( ( ♯ ‘ ( 𝑆 ‘ 𝑎 ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  →  ( ( 𝑆 ‘ 𝑎 )  =  ( 𝑆 ‘ 𝑏 )  →  ( 𝑎 ‘ 0 )  =  ( 𝑏 ‘ 0 ) ) ) )  →  ( ( ♯ ‘ ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  →  ( ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  =  ( 𝑆 ‘ ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 ) )  →  ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ 0 )  =  ( ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 ) ‘ 0 ) ) ) ) | 
						
							| 142 | 95 124 7 141 | syl21anc | ⊢ ( 𝜑  →  ( ( ♯ ‘ ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  →  ( ( 𝑆 ‘ ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) )  =  ( 𝑆 ‘ ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 ) )  →  ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ 0 )  =  ( ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 ) ‘ 0 ) ) ) ) | 
						
							| 143 | 120 127 142 | mp2d | ⊢ ( 𝜑  →  ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ 0 )  =  ( ( 𝐶  ++  〈“ ( 𝐴 ‘ 𝐾 ) ”〉 ) ‘ 0 ) ) | 
						
							| 144 | 81 75 | sselid | ⊢ ( 𝜑  →  ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 145 |  | lencl | ⊢ ( ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  ∈  ℕ0 ) | 
						
							| 146 | 144 145 | syl | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  ∈  ℕ0 ) | 
						
							| 147 | 146 | nn0red | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  ∈  ℝ ) | 
						
							| 148 |  | ltaddrp | ⊢ ( ( ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  ∈  ℝ  ∧  2  ∈  ℝ+ )  →  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  <  ( ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  +  2 ) ) | 
						
							| 149 | 147 86 148 | sylancl | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  <  ( ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  +  2 ) ) | 
						
							| 150 | 65 | nn0red | ⊢ ( 𝜑  →  ( ♯ ‘ 𝐵 )  ∈  ℝ ) | 
						
							| 151 | 150 | lem1d | ⊢ ( 𝜑  →  ( ( ♯ ‘ 𝐵 )  −  1 )  ≤  ( ♯ ‘ 𝐵 ) ) | 
						
							| 152 |  | fznn | ⊢ ( ( ♯ ‘ 𝐵 )  ∈  ℤ  →  ( ( ( ♯ ‘ 𝐵 )  −  1 )  ∈  ( 1 ... ( ♯ ‘ 𝐵 ) )  ↔  ( ( ( ♯ ‘ 𝐵 )  −  1 )  ∈  ℕ  ∧  ( ( ♯ ‘ 𝐵 )  −  1 )  ≤  ( ♯ ‘ 𝐵 ) ) ) ) | 
						
							| 153 | 66 152 | syl | ⊢ ( 𝜑  →  ( ( ( ♯ ‘ 𝐵 )  −  1 )  ∈  ( 1 ... ( ♯ ‘ 𝐵 ) )  ↔  ( ( ( ♯ ‘ 𝐵 )  −  1 )  ∈  ℕ  ∧  ( ( ♯ ‘ 𝐵 )  −  1 )  ≤  ( ♯ ‘ 𝐵 ) ) ) ) | 
						
							| 154 | 70 151 153 | mpbir2and | ⊢ ( 𝜑  →  ( ( ♯ ‘ 𝐵 )  −  1 )  ∈  ( 1 ... ( ♯ ‘ 𝐵 ) ) ) | 
						
							| 155 | 1 2 3 4 5 6 | efgsres | ⊢ ( ( 𝐵  ∈  dom  𝑆  ∧  ( ( ♯ ‘ 𝐵 )  −  1 )  ∈  ( 1 ... ( ♯ ‘ 𝐵 ) ) )  →  ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) )  ∈  dom  𝑆 ) | 
						
							| 156 | 9 154 155 | syl2anc | ⊢ ( 𝜑  →  ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) )  ∈  dom  𝑆 ) | 
						
							| 157 | 1 2 3 4 5 6 | efgsval | ⊢ ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) )  ∈  dom  𝑆  →  ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  =  ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ ( ( ♯ ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  −  1 ) ) ) | 
						
							| 158 | 156 157 | syl | ⊢ ( 𝜑  →  ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  =  ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ ( ( ♯ ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  −  1 ) ) ) | 
						
							| 159 |  | fz1ssfz0 | ⊢ ( 1 ... ( ♯ ‘ 𝐵 ) )  ⊆  ( 0 ... ( ♯ ‘ 𝐵 ) ) | 
						
							| 160 | 159 154 | sselid | ⊢ ( 𝜑  →  ( ( ♯ ‘ 𝐵 )  −  1 )  ∈  ( 0 ... ( ♯ ‘ 𝐵 ) ) ) | 
						
							| 161 |  | pfxres | ⊢ ( ( 𝐵  ∈  Word  𝑊  ∧  ( ( ♯ ‘ 𝐵 )  −  1 )  ∈  ( 0 ... ( ♯ ‘ 𝐵 ) ) )  →  ( 𝐵  prefix  ( ( ♯ ‘ 𝐵 )  −  1 ) )  =  ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ) | 
						
							| 162 | 60 160 161 | syl2anc | ⊢ ( 𝜑  →  ( 𝐵  prefix  ( ( ♯ ‘ 𝐵 )  −  1 ) )  =  ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ) | 
						
							| 163 | 162 | fveq2d | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐵  prefix  ( ( ♯ ‘ 𝐵 )  −  1 ) ) )  =  ( ♯ ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ) ) | 
						
							| 164 |  | pfxlen | ⊢ ( ( 𝐵  ∈  Word  𝑊  ∧  ( ( ♯ ‘ 𝐵 )  −  1 )  ∈  ( 0 ... ( ♯ ‘ 𝐵 ) ) )  →  ( ♯ ‘ ( 𝐵  prefix  ( ( ♯ ‘ 𝐵 )  −  1 ) ) )  =  ( ( ♯ ‘ 𝐵 )  −  1 ) ) | 
						
							| 165 | 60 160 164 | syl2anc | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐵  prefix  ( ( ♯ ‘ 𝐵 )  −  1 ) ) )  =  ( ( ♯ ‘ 𝐵 )  −  1 ) ) | 
						
							| 166 | 163 165 | eqtr3d | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  =  ( ( ♯ ‘ 𝐵 )  −  1 ) ) | 
						
							| 167 | 166 | oveq1d | ⊢ ( 𝜑  →  ( ( ♯ ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  −  1 )  =  ( ( ( ♯ ‘ 𝐵 )  −  1 )  −  1 ) ) | 
						
							| 168 | 167 13 | eqtr4di | ⊢ ( 𝜑  →  ( ( ♯ ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  −  1 )  =  𝐿 ) | 
						
							| 169 | 168 | fveq2d | ⊢ ( 𝜑  →  ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ ( ( ♯ ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  −  1 ) )  =  ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ 𝐿 ) ) | 
						
							| 170 | 73 | fvresd | ⊢ ( 𝜑  →  ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ 𝐿 )  =  ( 𝐵 ‘ 𝐿 ) ) | 
						
							| 171 | 158 169 170 | 3eqtrd | ⊢ ( 𝜑  →  ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  =  ( 𝐵 ‘ 𝐿 ) ) | 
						
							| 172 | 171 | fveq2d | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ) )  =  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) ) | 
						
							| 173 | 1 2 3 4 5 6 | efgsdmi | ⊢ ( ( 𝐵  ∈  dom  𝑆  ∧  ( ( ♯ ‘ 𝐵 )  −  1 )  ∈  ℕ )  →  ( 𝑆 ‘ 𝐵 )  ∈  ran  ( 𝑇 ‘ ( 𝐵 ‘ ( ( ( ♯ ‘ 𝐵 )  −  1 )  −  1 ) ) ) ) | 
						
							| 174 | 9 70 173 | syl2anc | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝐵 )  ∈  ran  ( 𝑇 ‘ ( 𝐵 ‘ ( ( ( ♯ ‘ 𝐵 )  −  1 )  −  1 ) ) ) ) | 
						
							| 175 | 10 174 | eqeltrd | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝐴 )  ∈  ran  ( 𝑇 ‘ ( 𝐵 ‘ ( ( ( ♯ ‘ 𝐵 )  −  1 )  −  1 ) ) ) ) | 
						
							| 176 | 13 | fveq2i | ⊢ ( 𝐵 ‘ 𝐿 )  =  ( 𝐵 ‘ ( ( ( ♯ ‘ 𝐵 )  −  1 )  −  1 ) ) | 
						
							| 177 | 176 | fveq2i | ⊢ ( 𝑇 ‘ ( 𝐵 ‘ 𝐿 ) )  =  ( 𝑇 ‘ ( 𝐵 ‘ ( ( ( ♯ ‘ 𝐵 )  −  1 )  −  1 ) ) ) | 
						
							| 178 | 177 | rneqi | ⊢ ran  ( 𝑇 ‘ ( 𝐵 ‘ 𝐿 ) )  =  ran  ( 𝑇 ‘ ( 𝐵 ‘ ( ( ( ♯ ‘ 𝐵 )  −  1 )  −  1 ) ) ) | 
						
							| 179 | 175 178 | eleqtrrdi | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝐴 )  ∈  ran  ( 𝑇 ‘ ( 𝐵 ‘ 𝐿 ) ) ) | 
						
							| 180 | 1 2 3 4 | efgtlen | ⊢ ( ( ( 𝐵 ‘ 𝐿 )  ∈  𝑊  ∧  ( 𝑆 ‘ 𝐴 )  ∈  ran  ( 𝑇 ‘ ( 𝐵 ‘ 𝐿 ) ) )  →  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  =  ( ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  +  2 ) ) | 
						
							| 181 | 75 179 180 | syl2anc | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  =  ( ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  +  2 ) ) | 
						
							| 182 | 149 172 181 | 3brtr4d | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) ) ) | 
						
							| 183 | 121 | simprd | ⊢ ( 𝜑  →  ( 𝐵 ‘ 𝐿 )  ∈  ran  ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) ) | 
						
							| 184 | 1 2 3 4 5 6 | efgsp1 | ⊢ ( ( 𝐶  ∈  dom  𝑆  ∧  ( 𝐵 ‘ 𝐿 )  ∈  ran  ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) )  →  ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 )  ∈  dom  𝑆 ) | 
						
							| 185 | 22 183 184 | syl2anc | ⊢ ( 𝜑  →  ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 )  ∈  dom  𝑆 ) | 
						
							| 186 | 1 2 3 4 5 6 | efgsval2 | ⊢ ( ( 𝐶  ∈  Word  𝑊  ∧  ( 𝐵 ‘ 𝐿 )  ∈  𝑊  ∧  ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 )  ∈  dom  𝑆 )  →  ( 𝑆 ‘ ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 ) )  =  ( 𝐵 ‘ 𝐿 ) ) | 
						
							| 187 | 27 75 185 186 | syl3anc | ⊢ ( 𝜑  →  ( 𝑆 ‘ ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 ) )  =  ( 𝐵 ‘ 𝐿 ) ) | 
						
							| 188 | 171 187 | eqtr4d | ⊢ ( 𝜑  →  ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  =  ( 𝑆 ‘ ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 ) ) ) | 
						
							| 189 |  | 2fveq3 | ⊢ ( 𝑎  =  ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) )  →  ( ♯ ‘ ( 𝑆 ‘ 𝑎 ) )  =  ( ♯ ‘ ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ) ) ) | 
						
							| 190 | 189 | breq1d | ⊢ ( 𝑎  =  ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) )  →  ( ( ♯ ‘ ( 𝑆 ‘ 𝑎 ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  ↔  ( ♯ ‘ ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) ) ) ) | 
						
							| 191 |  | fveqeq2 | ⊢ ( 𝑎  =  ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) )  →  ( ( 𝑆 ‘ 𝑎 )  =  ( 𝑆 ‘ 𝑏 )  ↔  ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  =  ( 𝑆 ‘ 𝑏 ) ) ) | 
						
							| 192 |  | fveq1 | ⊢ ( 𝑎  =  ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) )  →  ( 𝑎 ‘ 0 )  =  ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ 0 ) ) | 
						
							| 193 | 192 | eqeq1d | ⊢ ( 𝑎  =  ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) )  →  ( ( 𝑎 ‘ 0 )  =  ( 𝑏 ‘ 0 )  ↔  ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ 0 )  =  ( 𝑏 ‘ 0 ) ) ) | 
						
							| 194 | 191 193 | imbi12d | ⊢ ( 𝑎  =  ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) )  →  ( ( ( 𝑆 ‘ 𝑎 )  =  ( 𝑆 ‘ 𝑏 )  →  ( 𝑎 ‘ 0 )  =  ( 𝑏 ‘ 0 ) )  ↔  ( ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  =  ( 𝑆 ‘ 𝑏 )  →  ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ 0 )  =  ( 𝑏 ‘ 0 ) ) ) ) | 
						
							| 195 | 190 194 | imbi12d | ⊢ ( 𝑎  =  ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) )  →  ( ( ( ♯ ‘ ( 𝑆 ‘ 𝑎 ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  →  ( ( 𝑆 ‘ 𝑎 )  =  ( 𝑆 ‘ 𝑏 )  →  ( 𝑎 ‘ 0 )  =  ( 𝑏 ‘ 0 ) ) )  ↔  ( ( ♯ ‘ ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  →  ( ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  =  ( 𝑆 ‘ 𝑏 )  →  ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ 0 )  =  ( 𝑏 ‘ 0 ) ) ) ) ) | 
						
							| 196 |  | fveq2 | ⊢ ( 𝑏  =  ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 )  →  ( 𝑆 ‘ 𝑏 )  =  ( 𝑆 ‘ ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 ) ) ) | 
						
							| 197 | 196 | eqeq2d | ⊢ ( 𝑏  =  ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 )  →  ( ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  =  ( 𝑆 ‘ 𝑏 )  ↔  ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  =  ( 𝑆 ‘ ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 ) ) ) ) | 
						
							| 198 |  | fveq1 | ⊢ ( 𝑏  =  ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 )  →  ( 𝑏 ‘ 0 )  =  ( ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 ) ‘ 0 ) ) | 
						
							| 199 | 198 | eqeq2d | ⊢ ( 𝑏  =  ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 )  →  ( ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ 0 )  =  ( 𝑏 ‘ 0 )  ↔  ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ 0 )  =  ( ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 ) ‘ 0 ) ) ) | 
						
							| 200 | 197 199 | imbi12d | ⊢ ( 𝑏  =  ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 )  →  ( ( ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  =  ( 𝑆 ‘ 𝑏 )  →  ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ 0 )  =  ( 𝑏 ‘ 0 ) )  ↔  ( ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  =  ( 𝑆 ‘ ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 ) )  →  ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ 0 )  =  ( ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 ) ‘ 0 ) ) ) ) | 
						
							| 201 | 200 | imbi2d | ⊢ ( 𝑏  =  ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 )  →  ( ( ( ♯ ‘ ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  →  ( ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  =  ( 𝑆 ‘ 𝑏 )  →  ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ 0 )  =  ( 𝑏 ‘ 0 ) ) )  ↔  ( ( ♯ ‘ ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  →  ( ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  =  ( 𝑆 ‘ ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 ) )  →  ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ 0 )  =  ( ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 ) ‘ 0 ) ) ) ) ) | 
						
							| 202 | 195 201 | rspc2va | ⊢ ( ( ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) )  ∈  dom  𝑆  ∧  ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 )  ∈  dom  𝑆 )  ∧  ∀ 𝑎  ∈  dom  𝑆 ∀ 𝑏  ∈  dom  𝑆 ( ( ♯ ‘ ( 𝑆 ‘ 𝑎 ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  →  ( ( 𝑆 ‘ 𝑎 )  =  ( 𝑆 ‘ 𝑏 )  →  ( 𝑎 ‘ 0 )  =  ( 𝑏 ‘ 0 ) ) ) )  →  ( ( ♯ ‘ ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  →  ( ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  =  ( 𝑆 ‘ ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 ) )  →  ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ 0 )  =  ( ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 ) ‘ 0 ) ) ) ) | 
						
							| 203 | 156 185 7 202 | syl21anc | ⊢ ( 𝜑  →  ( ( ♯ ‘ ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ) )  <  ( ♯ ‘ ( 𝑆 ‘ 𝐴 ) )  →  ( ( 𝑆 ‘ ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) )  =  ( 𝑆 ‘ ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 ) )  →  ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ 0 )  =  ( ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 ) ‘ 0 ) ) ) ) | 
						
							| 204 | 182 188 203 | mp2d | ⊢ ( 𝜑  →  ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ 0 )  =  ( ( 𝐶  ++  〈“ ( 𝐵 ‘ 𝐿 ) ”〉 ) ‘ 0 ) ) | 
						
							| 205 | 79 143 204 | 3eqtr4d | ⊢ ( 𝜑  →  ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ 0 )  =  ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ 0 ) ) | 
						
							| 206 |  | lbfzo0 | ⊢ ( 0  ∈  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) )  ↔  ( ( ♯ ‘ 𝐴 )  −  1 )  ∈  ℕ ) | 
						
							| 207 | 42 206 | sylibr | ⊢ ( 𝜑  →  0  ∈  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) | 
						
							| 208 | 207 | fvresd | ⊢ ( 𝜑  →  ( ( 𝐴  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐴 )  −  1 ) ) ) ‘ 0 )  =  ( 𝐴 ‘ 0 ) ) | 
						
							| 209 |  | lbfzo0 | ⊢ ( 0  ∈  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) )  ↔  ( ( ♯ ‘ 𝐵 )  −  1 )  ∈  ℕ ) | 
						
							| 210 | 70 209 | sylibr | ⊢ ( 𝜑  →  0  ∈  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) | 
						
							| 211 | 210 | fvresd | ⊢ ( 𝜑  →  ( ( 𝐵  ↾  ( 0 ..^ ( ( ♯ ‘ 𝐵 )  −  1 ) ) ) ‘ 0 )  =  ( 𝐵 ‘ 0 ) ) | 
						
							| 212 | 205 208 211 | 3eqtr3d | ⊢ ( 𝜑  →  ( 𝐴 ‘ 0 )  =  ( 𝐵 ‘ 0 ) ) |