| 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 | efgsf | ⊢ 𝑆 : { 𝑡  ∈  ( Word  𝑊  ∖  { ∅ } )  ∣  ( ( 𝑡 ‘ 0 )  ∈  𝐷  ∧  ∀ 𝑘  ∈  ( 1 ..^ ( ♯ ‘ 𝑡 ) ) ( 𝑡 ‘ 𝑘 )  ∈  ran  ( 𝑇 ‘ ( 𝑡 ‘ ( 𝑘  −  1 ) ) ) ) } ⟶ 𝑊 | 
						
							| 25 | 24 | fdmi | ⊢ dom  𝑆  =  { 𝑡  ∈  ( Word  𝑊  ∖  { ∅ } )  ∣  ( ( 𝑡 ‘ 0 )  ∈  𝐷  ∧  ∀ 𝑘  ∈  ( 1 ..^ ( ♯ ‘ 𝑡 ) ) ( 𝑡 ‘ 𝑘 )  ∈  ran  ( 𝑇 ‘ ( 𝑡 ‘ ( 𝑘  −  1 ) ) ) ) } | 
						
							| 26 | 25 | feq2i | ⊢ ( 𝑆 : dom  𝑆 ⟶ 𝑊  ↔  𝑆 : { 𝑡  ∈  ( Word  𝑊  ∖  { ∅ } )  ∣  ( ( 𝑡 ‘ 0 )  ∈  𝐷  ∧  ∀ 𝑘  ∈  ( 1 ..^ ( ♯ ‘ 𝑡 ) ) ( 𝑡 ‘ 𝑘 )  ∈  ran  ( 𝑇 ‘ ( 𝑡 ‘ ( 𝑘  −  1 ) ) ) ) } ⟶ 𝑊 ) | 
						
							| 27 | 24 26 | mpbir | ⊢ 𝑆 : dom  𝑆 ⟶ 𝑊 | 
						
							| 28 | 27 | ffvelcdmi | ⊢ ( 𝐶  ∈  dom  𝑆  →  ( 𝑆 ‘ 𝐶 )  ∈  𝑊 ) | 
						
							| 29 | 22 28 | syl | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝐶 )  ∈  𝑊 ) | 
						
							| 30 |  | elfzuz | ⊢ ( 𝑄  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) )  →  𝑄  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 31 | 15 30 | syl | ⊢ ( 𝜑  →  𝑄  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 32 | 23 | fveq2d | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) )  =  ( ♯ ‘ ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) ) | 
						
							| 33 |  | fviss | ⊢ (  I  ‘ Word  ( 𝐼  ×  2o ) )  ⊆  Word  ( 𝐼  ×  2o ) | 
						
							| 34 | 1 33 | eqsstri | ⊢ 𝑊  ⊆  Word  ( 𝐼  ×  2o ) | 
						
							| 35 | 1 2 3 4 5 6 7 8 9 10 11 12 13 | efgredlemf | ⊢ ( 𝜑  →  ( ( 𝐴 ‘ 𝐾 )  ∈  𝑊  ∧  ( 𝐵 ‘ 𝐿 )  ∈  𝑊 ) ) | 
						
							| 36 | 35 | simprd | ⊢ ( 𝜑  →  ( 𝐵 ‘ 𝐿 )  ∈  𝑊 ) | 
						
							| 37 | 34 36 | sselid | ⊢ ( 𝜑  →  ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 38 |  | pfxcl | ⊢ ( ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 39 | 37 38 | syl | ⊢ ( 𝜑  →  ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 40 | 35 | simpld | ⊢ ( 𝜑  →  ( 𝐴 ‘ 𝐾 )  ∈  𝑊 ) | 
						
							| 41 | 34 40 | sselid | ⊢ ( 𝜑  →  ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 42 |  | swrdcl | ⊢ ( ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 43 | 41 42 | syl | ⊢ ( 𝜑  →  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 44 |  | ccatlen | ⊢ ( ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) )  →  ( ♯ ‘ ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 ) )  +  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) ) | 
						
							| 45 | 39 43 44 | syl2anc | ⊢ ( 𝜑  →  ( ♯ ‘ ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 ) )  +  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) ) | 
						
							| 46 |  | pfxlen | ⊢ ( ( ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o )  ∧  𝑄  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) ) )  →  ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 ) )  =  𝑄 ) | 
						
							| 47 | 37 15 46 | syl2anc | ⊢ ( 𝜑  →  ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 ) )  =  𝑄 ) | 
						
							| 48 |  | 2nn0 | ⊢ 2  ∈  ℕ0 | 
						
							| 49 |  | uzaddcl | ⊢ ( ( 𝑄  ∈  ( ℤ≥ ‘ 0 )  ∧  2  ∈  ℕ0 )  →  ( 𝑄  +  2 )  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 50 | 31 48 49 | sylancl | ⊢ ( 𝜑  →  ( 𝑄  +  2 )  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 51 |  | elfzuz3 | ⊢ ( 𝑃  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) )  →  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ( ℤ≥ ‘ 𝑃 ) ) | 
						
							| 52 | 14 51 | syl | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ( ℤ≥ ‘ 𝑃 ) ) | 
						
							| 53 |  | uztrn | ⊢ ( ( ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ( ℤ≥ ‘ 𝑃 )  ∧  𝑃  ∈  ( ℤ≥ ‘ ( 𝑄  +  2 ) ) )  →  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ( ℤ≥ ‘ ( 𝑄  +  2 ) ) ) | 
						
							| 54 | 52 21 53 | syl2anc | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ( ℤ≥ ‘ ( 𝑄  +  2 ) ) ) | 
						
							| 55 |  | elfzuzb | ⊢ ( ( 𝑄  +  2 )  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) )  ↔  ( ( 𝑄  +  2 )  ∈  ( ℤ≥ ‘ 0 )  ∧  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ( ℤ≥ ‘ ( 𝑄  +  2 ) ) ) ) | 
						
							| 56 | 50 54 55 | sylanbrc | ⊢ ( 𝜑  →  ( 𝑄  +  2 )  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) ) ) | 
						
							| 57 |  | lencl | ⊢ ( ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ℕ0 ) | 
						
							| 58 | 41 57 | syl | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ℕ0 ) | 
						
							| 59 |  | nn0uz | ⊢ ℕ0  =  ( ℤ≥ ‘ 0 ) | 
						
							| 60 | 58 59 | eleqtrdi | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 61 |  | eluzfz2 | ⊢ ( ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ( ℤ≥ ‘ 0 )  →  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) ) ) | 
						
							| 62 | 60 61 | syl | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) ) ) | 
						
							| 63 |  | swrdlen | ⊢ ( ( ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( 𝑄  +  2 )  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) )  ∧  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) ) )  →  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  −  ( 𝑄  +  2 ) ) ) | 
						
							| 64 | 41 56 62 63 | syl3anc | ⊢ ( 𝜑  →  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  −  ( 𝑄  +  2 ) ) ) | 
						
							| 65 | 47 64 | oveq12d | ⊢ ( 𝜑  →  ( ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 ) )  +  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( 𝑄  +  ( ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  −  ( 𝑄  +  2 ) ) ) ) | 
						
							| 66 | 15 | elfzelzd | ⊢ ( 𝜑  →  𝑄  ∈  ℤ ) | 
						
							| 67 | 66 | zcnd | ⊢ ( 𝜑  →  𝑄  ∈  ℂ ) | 
						
							| 68 | 58 | nn0cnd | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ℂ ) | 
						
							| 69 |  | 2z | ⊢ 2  ∈  ℤ | 
						
							| 70 |  | zaddcl | ⊢ ( ( 𝑄  ∈  ℤ  ∧  2  ∈  ℤ )  →  ( 𝑄  +  2 )  ∈  ℤ ) | 
						
							| 71 | 66 69 70 | sylancl | ⊢ ( 𝜑  →  ( 𝑄  +  2 )  ∈  ℤ ) | 
						
							| 72 | 71 | zcnd | ⊢ ( 𝜑  →  ( 𝑄  +  2 )  ∈  ℂ ) | 
						
							| 73 | 67 68 72 | addsubassd | ⊢ ( 𝜑  →  ( ( 𝑄  +  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) )  −  ( 𝑄  +  2 ) )  =  ( 𝑄  +  ( ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  −  ( 𝑄  +  2 ) ) ) ) | 
						
							| 74 |  | 2cn | ⊢ 2  ∈  ℂ | 
						
							| 75 | 74 | a1i | ⊢ ( 𝜑  →  2  ∈  ℂ ) | 
						
							| 76 | 67 68 75 | pnpcand | ⊢ ( 𝜑  →  ( ( 𝑄  +  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) )  −  ( 𝑄  +  2 ) )  =  ( ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  −  2 ) ) | 
						
							| 77 | 65 73 76 | 3eqtr2d | ⊢ ( 𝜑  →  ( ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 ) )  +  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  −  2 ) ) | 
						
							| 78 | 32 45 77 | 3eqtrd | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) )  =  ( ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  −  2 ) ) | 
						
							| 79 | 14 | elfzelzd | ⊢ ( 𝜑  →  𝑃  ∈  ℤ ) | 
						
							| 80 |  | zsubcl | ⊢ ( ( 𝑃  ∈  ℤ  ∧  2  ∈  ℤ )  →  ( 𝑃  −  2 )  ∈  ℤ ) | 
						
							| 81 | 79 69 80 | sylancl | ⊢ ( 𝜑  →  ( 𝑃  −  2 )  ∈  ℤ ) | 
						
							| 82 | 69 | a1i | ⊢ ( 𝜑  →  2  ∈  ℤ ) | 
						
							| 83 | 79 | zcnd | ⊢ ( 𝜑  →  𝑃  ∈  ℂ ) | 
						
							| 84 |  | npcan | ⊢ ( ( 𝑃  ∈  ℂ  ∧  2  ∈  ℂ )  →  ( ( 𝑃  −  2 )  +  2 )  =  𝑃 ) | 
						
							| 85 | 83 74 84 | sylancl | ⊢ ( 𝜑  →  ( ( 𝑃  −  2 )  +  2 )  =  𝑃 ) | 
						
							| 86 | 85 | fveq2d | ⊢ ( 𝜑  →  ( ℤ≥ ‘ ( ( 𝑃  −  2 )  +  2 ) )  =  ( ℤ≥ ‘ 𝑃 ) ) | 
						
							| 87 | 52 86 | eleqtrrd | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ( ℤ≥ ‘ ( ( 𝑃  −  2 )  +  2 ) ) ) | 
						
							| 88 |  | eluzsub | ⊢ ( ( ( 𝑃  −  2 )  ∈  ℤ  ∧  2  ∈  ℤ  ∧  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ( ℤ≥ ‘ ( ( 𝑃  −  2 )  +  2 ) ) )  →  ( ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  −  2 )  ∈  ( ℤ≥ ‘ ( 𝑃  −  2 ) ) ) | 
						
							| 89 | 81 82 87 88 | syl3anc | ⊢ ( 𝜑  →  ( ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  −  2 )  ∈  ( ℤ≥ ‘ ( 𝑃  −  2 ) ) ) | 
						
							| 90 | 78 89 | eqeltrd | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) )  ∈  ( ℤ≥ ‘ ( 𝑃  −  2 ) ) ) | 
						
							| 91 |  | eluzsub | ⊢ ( ( 𝑄  ∈  ℤ  ∧  2  ∈  ℤ  ∧  𝑃  ∈  ( ℤ≥ ‘ ( 𝑄  +  2 ) ) )  →  ( 𝑃  −  2 )  ∈  ( ℤ≥ ‘ 𝑄 ) ) | 
						
							| 92 | 66 82 21 91 | syl3anc | ⊢ ( 𝜑  →  ( 𝑃  −  2 )  ∈  ( ℤ≥ ‘ 𝑄 ) ) | 
						
							| 93 |  | uztrn | ⊢ ( ( ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) )  ∈  ( ℤ≥ ‘ ( 𝑃  −  2 ) )  ∧  ( 𝑃  −  2 )  ∈  ( ℤ≥ ‘ 𝑄 ) )  →  ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) )  ∈  ( ℤ≥ ‘ 𝑄 ) ) | 
						
							| 94 | 90 92 93 | syl2anc | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) )  ∈  ( ℤ≥ ‘ 𝑄 ) ) | 
						
							| 95 |  | elfzuzb | ⊢ ( 𝑄  ∈  ( 0 ... ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) ) )  ↔  ( 𝑄  ∈  ( ℤ≥ ‘ 0 )  ∧  ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) )  ∈  ( ℤ≥ ‘ 𝑄 ) ) ) | 
						
							| 96 | 31 94 95 | sylanbrc | ⊢ ( 𝜑  →  𝑄  ∈  ( 0 ... ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) ) ) ) | 
						
							| 97 | 1 2 3 4 | efgtval | ⊢ ( ( ( 𝑆 ‘ 𝐶 )  ∈  𝑊  ∧  𝑄  ∈  ( 0 ... ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) ) )  ∧  𝑉  ∈  ( 𝐼  ×  2o ) )  →  ( 𝑄 ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) 𝑉 )  =  ( ( 𝑆 ‘ 𝐶 )  splice  〈 𝑄 ,  𝑄 ,  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 〉 ) ) | 
						
							| 98 | 29 96 17 97 | syl3anc | ⊢ ( 𝜑  →  ( 𝑄 ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) 𝑉 )  =  ( ( 𝑆 ‘ 𝐶 )  splice  〈 𝑄 ,  𝑄 ,  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 〉 ) ) | 
						
							| 99 |  | pfxcl | ⊢ ( ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 100 | 41 99 | syl | ⊢ ( 𝜑  →  ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 101 |  | wrd0 | ⊢ ∅  ∈  Word  ( 𝐼  ×  2o ) | 
						
							| 102 | 101 | a1i | ⊢ ( 𝜑  →  ∅  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 103 | 3 | efgmf | ⊢ 𝑀 : ( 𝐼  ×  2o ) ⟶ ( 𝐼  ×  2o ) | 
						
							| 104 | 103 | ffvelcdmi | ⊢ ( 𝑉  ∈  ( 𝐼  ×  2o )  →  ( 𝑀 ‘ 𝑉 )  ∈  ( 𝐼  ×  2o ) ) | 
						
							| 105 | 17 104 | syl | ⊢ ( 𝜑  →  ( 𝑀 ‘ 𝑉 )  ∈  ( 𝐼  ×  2o ) ) | 
						
							| 106 | 17 105 | s2cld | ⊢ ( 𝜑  →  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 107 | 66 | zred | ⊢ ( 𝜑  →  𝑄  ∈  ℝ ) | 
						
							| 108 |  | nn0addge1 | ⊢ ( ( 𝑄  ∈  ℝ  ∧  2  ∈  ℕ0 )  →  𝑄  ≤  ( 𝑄  +  2 ) ) | 
						
							| 109 | 107 48 108 | sylancl | ⊢ ( 𝜑  →  𝑄  ≤  ( 𝑄  +  2 ) ) | 
						
							| 110 |  | eluz2 | ⊢ ( ( 𝑄  +  2 )  ∈  ( ℤ≥ ‘ 𝑄 )  ↔  ( 𝑄  ∈  ℤ  ∧  ( 𝑄  +  2 )  ∈  ℤ  ∧  𝑄  ≤  ( 𝑄  +  2 ) ) ) | 
						
							| 111 | 66 71 109 110 | syl3anbrc | ⊢ ( 𝜑  →  ( 𝑄  +  2 )  ∈  ( ℤ≥ ‘ 𝑄 ) ) | 
						
							| 112 |  | uztrn | ⊢ ( ( 𝑃  ∈  ( ℤ≥ ‘ ( 𝑄  +  2 ) )  ∧  ( 𝑄  +  2 )  ∈  ( ℤ≥ ‘ 𝑄 ) )  →  𝑃  ∈  ( ℤ≥ ‘ 𝑄 ) ) | 
						
							| 113 | 21 111 112 | syl2anc | ⊢ ( 𝜑  →  𝑃  ∈  ( ℤ≥ ‘ 𝑄 ) ) | 
						
							| 114 |  | elfzuzb | ⊢ ( 𝑄  ∈  ( 0 ... 𝑃 )  ↔  ( 𝑄  ∈  ( ℤ≥ ‘ 0 )  ∧  𝑃  ∈  ( ℤ≥ ‘ 𝑄 ) ) ) | 
						
							| 115 | 31 113 114 | sylanbrc | ⊢ ( 𝜑  →  𝑄  ∈  ( 0 ... 𝑃 ) ) | 
						
							| 116 |  | ccatpfx | ⊢ ( ( ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o )  ∧  𝑄  ∈  ( 0 ... 𝑃 )  ∧  𝑃  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) ) )  →  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 ) )  =  ( ( 𝐴 ‘ 𝐾 )  prefix  𝑃 ) ) | 
						
							| 117 | 41 115 14 116 | syl3anc | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 ) )  =  ( ( 𝐴 ‘ 𝐾 )  prefix  𝑃 ) ) | 
						
							| 118 | 117 | oveq1d | ⊢ ( 𝜑  →  ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 ) )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑃 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) ) | 
						
							| 119 |  | pfxcl | ⊢ ( ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ( 𝐴 ‘ 𝐾 )  prefix  𝑃 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 120 | 41 119 | syl | ⊢ ( 𝜑  →  ( ( 𝐴 ‘ 𝐾 )  prefix  𝑃 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 121 | 103 | ffvelcdmi | ⊢ ( 𝑈  ∈  ( 𝐼  ×  2o )  →  ( 𝑀 ‘ 𝑈 )  ∈  ( 𝐼  ×  2o ) ) | 
						
							| 122 | 16 121 | syl | ⊢ ( 𝜑  →  ( 𝑀 ‘ 𝑈 )  ∈  ( 𝐼  ×  2o ) ) | 
						
							| 123 | 16 122 | s2cld | ⊢ ( 𝜑  →  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 124 |  | swrdcl | ⊢ ( ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 125 | 41 124 | syl | ⊢ ( 𝜑  →  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 126 |  | ccatass | ⊢ ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑃 )  ∈  Word  ( 𝐼  ×  2o )  ∧  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ∈  Word  ( 𝐼  ×  2o )  ∧  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) )  →  ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑃 )  ++  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑃 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) ) | 
						
							| 127 | 120 123 125 126 | syl3anc | ⊢ ( 𝜑  →  ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑃 )  ++  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑃 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) ) | 
						
							| 128 | 1 2 3 4 | efgtval | ⊢ ( ( ( 𝐴 ‘ 𝐾 )  ∈  𝑊  ∧  𝑃  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) )  ∧  𝑈  ∈  ( 𝐼  ×  2o ) )  →  ( 𝑃 ( 𝑇 ‘ ( 𝐴 ‘ 𝐾 ) ) 𝑈 )  =  ( ( 𝐴 ‘ 𝐾 )  splice  〈 𝑃 ,  𝑃 ,  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 〉 ) ) | 
						
							| 129 | 40 14 16 128 | syl3anc | ⊢ ( 𝜑  →  ( 𝑃 ( 𝑇 ‘ ( 𝐴 ‘ 𝐾 ) ) 𝑈 )  =  ( ( 𝐴 ‘ 𝐾 )  splice  〈 𝑃 ,  𝑃 ,  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 〉 ) ) | 
						
							| 130 |  | splval | ⊢ ( ( ( 𝐴 ‘ 𝐾 )  ∈  𝑊  ∧  ( 𝑃  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) )  ∧  𝑃  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) )  ∧  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ∈  Word  ( 𝐼  ×  2o ) ) )  →  ( ( 𝐴 ‘ 𝐾 )  splice  〈 𝑃 ,  𝑃 ,  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 〉 )  =  ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑃 )  ++  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) | 
						
							| 131 | 40 14 14 123 130 | syl13anc | ⊢ ( 𝜑  →  ( ( 𝐴 ‘ 𝐾 )  splice  〈 𝑃 ,  𝑃 ,  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 〉 )  =  ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑃 )  ++  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) | 
						
							| 132 | 18 129 131 | 3eqtrd | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝐴 )  =  ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑃 )  ++  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) | 
						
							| 133 | 1 2 3 4 | efgtval | ⊢ ( ( ( 𝐵 ‘ 𝐿 )  ∈  𝑊  ∧  𝑄  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) )  ∧  𝑉  ∈  ( 𝐼  ×  2o ) )  →  ( 𝑄 ( 𝑇 ‘ ( 𝐵 ‘ 𝐿 ) ) 𝑉 )  =  ( ( 𝐵 ‘ 𝐿 )  splice  〈 𝑄 ,  𝑄 ,  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 〉 ) ) | 
						
							| 134 | 36 15 17 133 | syl3anc | ⊢ ( 𝜑  →  ( 𝑄 ( 𝑇 ‘ ( 𝐵 ‘ 𝐿 ) ) 𝑉 )  =  ( ( 𝐵 ‘ 𝐿 )  splice  〈 𝑄 ,  𝑄 ,  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 〉 ) ) | 
						
							| 135 |  | splval | ⊢ ( ( ( 𝐵 ‘ 𝐿 )  ∈  𝑊  ∧  ( 𝑄  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) )  ∧  𝑄  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) )  ∧  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ∈  Word  ( 𝐼  ×  2o ) ) )  →  ( ( 𝐵 ‘ 𝐿 )  splice  〈 𝑄 ,  𝑄 ,  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 〉 )  =  ( ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 136 | 36 15 15 106 135 | syl13anc | ⊢ ( 𝜑  →  ( ( 𝐵 ‘ 𝐿 )  splice  〈 𝑄 ,  𝑄 ,  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 〉 )  =  ( ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 137 | 19 134 136 | 3eqtrd | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝐵 )  =  ( ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 138 | 10 132 137 | 3eqtr3d | ⊢ ( 𝜑  →  ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑃 )  ++  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 139 | 118 127 138 | 3eqtr2d | ⊢ ( 𝜑  →  ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 ) )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 140 |  | swrdcl | ⊢ ( ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 141 | 41 140 | syl | ⊢ ( 𝜑  →  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 142 |  | ccatcl | ⊢ ( ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ∈  Word  ( 𝐼  ×  2o )  ∧  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) )  →  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 143 | 123 125 142 | syl2anc | ⊢ ( 𝜑  →  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 144 |  | ccatass | ⊢ ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  ∈  Word  ( 𝐼  ×  2o ) )  →  ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 ) )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) ) ) | 
						
							| 145 | 100 141 143 144 | syl3anc | ⊢ ( 𝜑  →  ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 ) )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) ) ) | 
						
							| 146 |  | swrdcl | ⊢ ( ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 147 | 37 146 | syl | ⊢ ( 𝜑  →  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 148 |  | ccatass | ⊢ ( ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ∈  Word  ( 𝐼  ×  2o )  ∧  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ∈  Word  ( 𝐼  ×  2o )  ∧  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) )  →  ( ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  =  ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) ) | 
						
							| 149 | 39 106 147 148 | syl3anc | ⊢ ( 𝜑  →  ( ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  =  ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) ) | 
						
							| 150 | 139 145 149 | 3eqtr3d | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) )  =  ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) ) | 
						
							| 151 |  | ccatcl | ⊢ ( ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  ∈  Word  ( 𝐼  ×  2o ) )  →  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 152 | 141 143 151 | syl2anc | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 153 |  | ccatcl | ⊢ ( ( 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ∈  Word  ( 𝐼  ×  2o )  ∧  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) )  →  ( 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 154 | 106 147 153 | syl2anc | ⊢ ( 𝜑  →  ( 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 155 |  | uztrn | ⊢ ( ( ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ( ℤ≥ ‘ 𝑃 )  ∧  𝑃  ∈  ( ℤ≥ ‘ 𝑄 ) )  →  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ( ℤ≥ ‘ 𝑄 ) ) | 
						
							| 156 | 52 113 155 | syl2anc | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ( ℤ≥ ‘ 𝑄 ) ) | 
						
							| 157 |  | elfzuzb | ⊢ ( 𝑄  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) )  ↔  ( 𝑄  ∈  ( ℤ≥ ‘ 0 )  ∧  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ( ℤ≥ ‘ 𝑄 ) ) ) | 
						
							| 158 | 31 156 157 | sylanbrc | ⊢ ( 𝜑  →  𝑄  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) ) ) | 
						
							| 159 |  | pfxlen | ⊢ ( ( ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o )  ∧  𝑄  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) ) )  →  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 ) )  =  𝑄 ) | 
						
							| 160 | 41 158 159 | syl2anc | ⊢ ( 𝜑  →  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 ) )  =  𝑄 ) | 
						
							| 161 | 160 47 | eqtr4d | ⊢ ( 𝜑  →  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 ) )  =  ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 ) ) ) | 
						
							| 162 |  | ccatopth | ⊢ ( ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  ∈  Word  ( 𝐼  ×  2o ) )  ∧  ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  ∈  Word  ( 𝐼  ×  2o ) )  ∧  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 ) )  =  ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 ) ) )  →  ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) )  =  ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) )  ↔  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  =  ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ∧  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) ) ) | 
						
							| 163 | 100 152 39 154 161 162 | syl221anc | ⊢ ( 𝜑  →  ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) )  =  ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) )  ↔  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  =  ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ∧  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) ) ) | 
						
							| 164 | 150 163 | mpbid | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  =  ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ∧  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) ) | 
						
							| 165 | 164 | simpld | ⊢ ( 𝜑  →  ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  =  ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 ) ) | 
						
							| 166 | 165 | oveq1d | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) | 
						
							| 167 |  | ccatrid | ⊢ ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ∅ )  =  ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 ) ) | 
						
							| 168 | 100 167 | syl | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ∅ )  =  ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 ) ) | 
						
							| 169 | 168 | oveq1d | ⊢ ( 𝜑  →  ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ∅ )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) | 
						
							| 170 | 166 169 23 | 3eqtr4rd | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝐶 )  =  ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ∅ )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) | 
						
							| 171 | 160 | eqcomd | ⊢ ( 𝜑  →  𝑄  =  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 ) ) ) | 
						
							| 172 |  | hash0 | ⊢ ( ♯ ‘ ∅ )  =  0 | 
						
							| 173 | 172 | oveq2i | ⊢ ( 𝑄  +  ( ♯ ‘ ∅ ) )  =  ( 𝑄  +  0 ) | 
						
							| 174 | 67 | addridd | ⊢ ( 𝜑  →  ( 𝑄  +  0 )  =  𝑄 ) | 
						
							| 175 | 173 174 | eqtr2id | ⊢ ( 𝜑  →  𝑄  =  ( 𝑄  +  ( ♯ ‘ ∅ ) ) ) | 
						
							| 176 | 100 102 43 106 170 171 175 | splval2 | ⊢ ( 𝜑  →  ( ( 𝑆 ‘ 𝐶 )  splice  〈 𝑄 ,  𝑄 ,  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 〉 )  =  ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) | 
						
							| 177 |  | elfzuzb | ⊢ ( 𝑄  ∈  ( 0 ... ( 𝑄  +  2 ) )  ↔  ( 𝑄  ∈  ( ℤ≥ ‘ 0 )  ∧  ( 𝑄  +  2 )  ∈  ( ℤ≥ ‘ 𝑄 ) ) ) | 
						
							| 178 | 31 111 177 | sylanbrc | ⊢ ( 𝜑  →  𝑄  ∈  ( 0 ... ( 𝑄  +  2 ) ) ) | 
						
							| 179 |  | elfzuzb | ⊢ ( ( 𝑄  +  2 )  ∈  ( 0 ... 𝑃 )  ↔  ( ( 𝑄  +  2 )  ∈  ( ℤ≥ ‘ 0 )  ∧  𝑃  ∈  ( ℤ≥ ‘ ( 𝑄  +  2 ) ) ) ) | 
						
							| 180 | 50 21 179 | sylanbrc | ⊢ ( 𝜑  →  ( 𝑄  +  2 )  ∈  ( 0 ... 𝑃 ) ) | 
						
							| 181 |  | ccatswrd | ⊢ ( ( ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( 𝑄  ∈  ( 0 ... ( 𝑄  +  2 ) )  ∧  ( 𝑄  +  2 )  ∈  ( 0 ... 𝑃 )  ∧  𝑃  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) ) ) )  →  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 ) )  =  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 ) ) | 
						
							| 182 | 41 178 180 14 181 | syl13anc | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 ) )  =  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 ) ) | 
						
							| 183 | 182 | oveq1d | ⊢ ( 𝜑  →  ( ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 ) )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) ) | 
						
							| 184 |  | swrdcl | ⊢ ( ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 185 | 41 184 | syl | ⊢ ( 𝜑  →  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 186 |  | swrdcl | ⊢ ( ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 187 | 41 186 | syl | ⊢ ( 𝜑  →  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 188 |  | ccatass | ⊢ ( ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  ∈  Word  ( 𝐼  ×  2o ) )  →  ( ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 ) )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 )  ++  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) ) ) | 
						
							| 189 | 185 187 143 188 | syl3anc | ⊢ ( 𝜑  →  ( ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 ) )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 )  ++  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) ) ) | 
						
							| 190 | 164 | simprd | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 191 | 183 189 190 | 3eqtr3d | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 )  ++  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) )  =  ( 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 192 |  | ccatcl | ⊢ ( ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  ∈  Word  ( 𝐼  ×  2o ) )  →  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 193 | 187 143 192 | syl2anc | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 194 |  | swrdlen | ⊢ ( ( ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o )  ∧  𝑄  ∈  ( 0 ... ( 𝑄  +  2 ) )  ∧  ( 𝑄  +  2 )  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) ) )  →  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 ) )  =  ( ( 𝑄  +  2 )  −  𝑄 ) ) | 
						
							| 195 | 41 178 56 194 | syl3anc | ⊢ ( 𝜑  →  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 ) )  =  ( ( 𝑄  +  2 )  −  𝑄 ) ) | 
						
							| 196 |  | pncan2 | ⊢ ( ( 𝑄  ∈  ℂ  ∧  2  ∈  ℂ )  →  ( ( 𝑄  +  2 )  −  𝑄 )  =  2 ) | 
						
							| 197 | 67 74 196 | sylancl | ⊢ ( 𝜑  →  ( ( 𝑄  +  2 )  −  𝑄 )  =  2 ) | 
						
							| 198 | 195 197 | eqtrd | ⊢ ( 𝜑  →  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 ) )  =  2 ) | 
						
							| 199 |  | s2len | ⊢ ( ♯ ‘ 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 )  =  2 | 
						
							| 200 | 198 199 | eqtr4di | ⊢ ( 𝜑  →  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 ) )  =  ( ♯ ‘ 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 ) ) | 
						
							| 201 |  | ccatopth | ⊢ ( ( ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  ∈  Word  ( 𝐼  ×  2o ) )  ∧  ( 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ∈  Word  ( 𝐼  ×  2o )  ∧  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) )  ∧  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 ) )  =  ( ♯ ‘ 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 ) )  →  ( ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 )  ++  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) )  =  ( 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  ↔  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 )  =  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ∧  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) ) | 
						
							| 202 | 185 193 106 147 200 201 | syl221anc | ⊢ ( 𝜑  →  ( ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 )  ++  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) )  =  ( 〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  ↔  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 )  =  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ∧  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) ) | 
						
							| 203 | 191 202 | mpbid | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 )  =  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉  ∧  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 204 | 203 | simpld | ⊢ ( 𝜑  →  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 )  =  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 ) | 
						
							| 205 | 204 | oveq2d | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 ) )  =  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 ) ) | 
						
							| 206 |  | ccatpfx | ⊢ ( ( ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o )  ∧  𝑄  ∈  ( 0 ... ( 𝑄  +  2 ) )  ∧  ( 𝑄  +  2 )  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) ) )  →  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 ) )  =  ( ( 𝐴 ‘ 𝐾 )  prefix  ( 𝑄  +  2 ) ) ) | 
						
							| 207 | 41 178 56 206 | syl3anc | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑄 ,  ( 𝑄  +  2 ) 〉 ) )  =  ( ( 𝐴 ‘ 𝐾 )  prefix  ( 𝑄  +  2 ) ) ) | 
						
							| 208 | 205 207 | eqtr3d | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 )  =  ( ( 𝐴 ‘ 𝐾 )  prefix  ( 𝑄  +  2 ) ) ) | 
						
							| 209 | 208 | oveq1d | ⊢ ( 𝜑  →  ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( ( 𝐴 ‘ 𝐾 )  prefix  ( 𝑄  +  2 ) )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) ) | 
						
							| 210 |  | ccatpfx | ⊢ ( ( ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( 𝑄  +  2 )  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) )  ∧  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) ) )  →  ( ( ( 𝐴 ‘ 𝐾 )  prefix  ( 𝑄  +  2 ) )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( 𝐴 ‘ 𝐾 )  prefix  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) ) ) | 
						
							| 211 | 41 56 62 210 | syl3anc | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  prefix  ( 𝑄  +  2 ) )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( 𝐴 ‘ 𝐾 )  prefix  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) ) ) | 
						
							| 212 |  | pfxid | ⊢ ( ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ( 𝐴 ‘ 𝐾 )  prefix  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) )  =  ( 𝐴 ‘ 𝐾 ) ) | 
						
							| 213 | 41 212 | syl | ⊢ ( 𝜑  →  ( ( 𝐴 ‘ 𝐾 )  prefix  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) )  =  ( 𝐴 ‘ 𝐾 ) ) | 
						
							| 214 | 209 211 213 | 3eqtrd | ⊢ ( 𝜑  →  ( ( ( ( 𝐴 ‘ 𝐾 )  prefix  𝑄 )  ++  〈“ 𝑉 ( 𝑀 ‘ 𝑉 ) ”〉 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( 𝐴 ‘ 𝐾 ) ) | 
						
							| 215 | 98 176 214 | 3eqtrd | ⊢ ( 𝜑  →  ( 𝑄 ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) 𝑉 )  =  ( 𝐴 ‘ 𝐾 ) ) | 
						
							| 216 | 1 2 3 4 | efgtf | ⊢ ( ( 𝑆 ‘ 𝐶 )  ∈  𝑊  →  ( ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) )  =  ( 𝑎  ∈  ( 0 ... ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) ) ) ,  𝑖  ∈  ( 𝐼  ×  2o )  ↦  ( ( 𝑆 ‘ 𝐶 )  splice  〈 𝑎 ,  𝑎 ,  〈“ 𝑖 ( 𝑀 ‘ 𝑖 ) ”〉 〉 ) )  ∧  ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) : ( ( 0 ... ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) ) )  ×  ( 𝐼  ×  2o ) ) ⟶ 𝑊 ) ) | 
						
							| 217 | 29 216 | syl | ⊢ ( 𝜑  →  ( ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) )  =  ( 𝑎  ∈  ( 0 ... ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) ) ) ,  𝑖  ∈  ( 𝐼  ×  2o )  ↦  ( ( 𝑆 ‘ 𝐶 )  splice  〈 𝑎 ,  𝑎 ,  〈“ 𝑖 ( 𝑀 ‘ 𝑖 ) ”〉 〉 ) )  ∧  ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) : ( ( 0 ... ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) ) )  ×  ( 𝐼  ×  2o ) ) ⟶ 𝑊 ) ) | 
						
							| 218 | 217 | simprd | ⊢ ( 𝜑  →  ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) : ( ( 0 ... ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) ) )  ×  ( 𝐼  ×  2o ) ) ⟶ 𝑊 ) | 
						
							| 219 | 218 | ffnd | ⊢ ( 𝜑  →  ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) )  Fn  ( ( 0 ... ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) ) )  ×  ( 𝐼  ×  2o ) ) ) | 
						
							| 220 |  | fnovrn | ⊢ ( ( ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) )  Fn  ( ( 0 ... ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) ) )  ×  ( 𝐼  ×  2o ) )  ∧  𝑄  ∈  ( 0 ... ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) ) )  ∧  𝑉  ∈  ( 𝐼  ×  2o ) )  →  ( 𝑄 ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) 𝑉 )  ∈  ran  ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) ) | 
						
							| 221 | 219 96 17 220 | syl3anc | ⊢ ( 𝜑  →  ( 𝑄 ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) 𝑉 )  ∈  ran  ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) ) | 
						
							| 222 | 215 221 | eqeltrrd | ⊢ ( 𝜑  →  ( 𝐴 ‘ 𝐾 )  ∈  ran  ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) ) | 
						
							| 223 |  | uztrn | ⊢ ( ( ( 𝑃  −  2 )  ∈  ( ℤ≥ ‘ 𝑄 )  ∧  𝑄  ∈  ( ℤ≥ ‘ 0 ) )  →  ( 𝑃  −  2 )  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 224 | 92 31 223 | syl2anc | ⊢ ( 𝜑  →  ( 𝑃  −  2 )  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 225 |  | elfzuzb | ⊢ ( ( 𝑃  −  2 )  ∈  ( 0 ... ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) ) )  ↔  ( ( 𝑃  −  2 )  ∈  ( ℤ≥ ‘ 0 )  ∧  ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) )  ∈  ( ℤ≥ ‘ ( 𝑃  −  2 ) ) ) ) | 
						
							| 226 | 224 90 225 | sylanbrc | ⊢ ( 𝜑  →  ( 𝑃  −  2 )  ∈  ( 0 ... ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) ) ) ) | 
						
							| 227 | 1 2 3 4 | efgtval | ⊢ ( ( ( 𝑆 ‘ 𝐶 )  ∈  𝑊  ∧  ( 𝑃  −  2 )  ∈  ( 0 ... ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) ) )  ∧  𝑈  ∈  ( 𝐼  ×  2o ) )  →  ( ( 𝑃  −  2 ) ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) 𝑈 )  =  ( ( 𝑆 ‘ 𝐶 )  splice  〈 ( 𝑃  −  2 ) ,  ( 𝑃  −  2 ) ,  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 〉 ) ) | 
						
							| 228 | 29 226 16 227 | syl3anc | ⊢ ( 𝜑  →  ( ( 𝑃  −  2 ) ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) 𝑈 )  =  ( ( 𝑆 ‘ 𝐶 )  splice  〈 ( 𝑃  −  2 ) ,  ( 𝑃  −  2 ) ,  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 〉 ) ) | 
						
							| 229 |  | pfxcl | ⊢ ( ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 230 | 37 229 | syl | ⊢ ( 𝜑  →  ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 231 |  | swrdcl | ⊢ ( ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 232 | 37 231 | syl | ⊢ ( 𝜑  →  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 233 |  | ccatswrd | ⊢ ( ( ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( ( 𝑄  +  2 )  ∈  ( 0 ... 𝑃 )  ∧  𝑃  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) )  ∧  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) ) ) )  →  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) | 
						
							| 234 | 41 180 14 62 233 | syl13anc | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) | 
						
							| 235 | 203 | simprd | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) | 
						
							| 236 |  | elfzuzb | ⊢ ( 𝑄  ∈  ( 0 ... ( 𝑃  −  2 ) )  ↔  ( 𝑄  ∈  ( ℤ≥ ‘ 0 )  ∧  ( 𝑃  −  2 )  ∈  ( ℤ≥ ‘ 𝑄 ) ) ) | 
						
							| 237 | 31 92 236 | sylanbrc | ⊢ ( 𝜑  →  𝑄  ∈  ( 0 ... ( 𝑃  −  2 ) ) ) | 
						
							| 238 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | efgredlemg | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) )  =  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) ) | 
						
							| 239 | 238 52 | eqeltrrd | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  ∈  ( ℤ≥ ‘ 𝑃 ) ) | 
						
							| 240 |  | 0le2 | ⊢ 0  ≤  2 | 
						
							| 241 | 240 | a1i | ⊢ ( 𝜑  →  0  ≤  2 ) | 
						
							| 242 | 79 | zred | ⊢ ( 𝜑  →  𝑃  ∈  ℝ ) | 
						
							| 243 |  | 2re | ⊢ 2  ∈  ℝ | 
						
							| 244 |  | subge02 | ⊢ ( ( 𝑃  ∈  ℝ  ∧  2  ∈  ℝ )  →  ( 0  ≤  2  ↔  ( 𝑃  −  2 )  ≤  𝑃 ) ) | 
						
							| 245 | 242 243 244 | sylancl | ⊢ ( 𝜑  →  ( 0  ≤  2  ↔  ( 𝑃  −  2 )  ≤  𝑃 ) ) | 
						
							| 246 | 241 245 | mpbid | ⊢ ( 𝜑  →  ( 𝑃  −  2 )  ≤  𝑃 ) | 
						
							| 247 |  | eluz2 | ⊢ ( 𝑃  ∈  ( ℤ≥ ‘ ( 𝑃  −  2 ) )  ↔  ( ( 𝑃  −  2 )  ∈  ℤ  ∧  𝑃  ∈  ℤ  ∧  ( 𝑃  −  2 )  ≤  𝑃 ) ) | 
						
							| 248 | 81 79 246 247 | syl3anbrc | ⊢ ( 𝜑  →  𝑃  ∈  ( ℤ≥ ‘ ( 𝑃  −  2 ) ) ) | 
						
							| 249 |  | uztrn | ⊢ ( ( ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  ∈  ( ℤ≥ ‘ 𝑃 )  ∧  𝑃  ∈  ( ℤ≥ ‘ ( 𝑃  −  2 ) ) )  →  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  ∈  ( ℤ≥ ‘ ( 𝑃  −  2 ) ) ) | 
						
							| 250 | 239 248 249 | syl2anc | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  ∈  ( ℤ≥ ‘ ( 𝑃  −  2 ) ) ) | 
						
							| 251 |  | elfzuzb | ⊢ ( ( 𝑃  −  2 )  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) )  ↔  ( ( 𝑃  −  2 )  ∈  ( ℤ≥ ‘ 0 )  ∧  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  ∈  ( ℤ≥ ‘ ( 𝑃  −  2 ) ) ) ) | 
						
							| 252 | 224 250 251 | sylanbrc | ⊢ ( 𝜑  →  ( 𝑃  −  2 )  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) ) ) | 
						
							| 253 |  | lencl | ⊢ ( ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  ∈  ℕ0 ) | 
						
							| 254 | 37 253 | syl | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  ∈  ℕ0 ) | 
						
							| 255 | 254 59 | eleqtrdi | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 256 |  | eluzfz2 | ⊢ ( ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  ∈  ( ℤ≥ ‘ 0 )  →  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) ) ) | 
						
							| 257 | 255 256 | syl | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) ) ) | 
						
							| 258 |  | ccatswrd | ⊢ ( ( ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( 𝑄  ∈  ( 0 ... ( 𝑃  −  2 ) )  ∧  ( 𝑃  −  2 )  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) )  ∧  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) ) ) )  →  ( ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) | 
						
							| 259 | 37 237 252 257 258 | syl13anc | ⊢ ( 𝜑  →  ( ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) | 
						
							| 260 | 235 259 | eqtr4d | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 261 |  | swrdcl | ⊢ ( ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 262 | 37 261 | syl | ⊢ ( 𝜑  →  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 263 |  | swrdcl | ⊢ ( ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 264 | 37 263 | syl | ⊢ ( 𝜑  →  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 265 |  | swrdlen | ⊢ ( ( ( 𝐴 ‘ 𝐾 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( 𝑄  +  2 )  ∈  ( 0 ... 𝑃 )  ∧  𝑃  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) ) )  →  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 ) )  =  ( 𝑃  −  ( 𝑄  +  2 ) ) ) | 
						
							| 266 | 41 180 14 265 | syl3anc | ⊢ ( 𝜑  →  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 ) )  =  ( 𝑃  −  ( 𝑄  +  2 ) ) ) | 
						
							| 267 |  | swrdlen | ⊢ ( ( ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o )  ∧  𝑄  ∈  ( 0 ... ( 𝑃  −  2 ) )  ∧  ( 𝑃  −  2 )  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) ) )  →  ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 ) )  =  ( ( 𝑃  −  2 )  −  𝑄 ) ) | 
						
							| 268 | 37 237 252 267 | syl3anc | ⊢ ( 𝜑  →  ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 ) )  =  ( ( 𝑃  −  2 )  −  𝑄 ) ) | 
						
							| 269 | 83 67 75 | sub32d | ⊢ ( 𝜑  →  ( ( 𝑃  −  𝑄 )  −  2 )  =  ( ( 𝑃  −  2 )  −  𝑄 ) ) | 
						
							| 270 | 83 67 75 | subsub4d | ⊢ ( 𝜑  →  ( ( 𝑃  −  𝑄 )  −  2 )  =  ( 𝑃  −  ( 𝑄  +  2 ) ) ) | 
						
							| 271 | 268 269 270 | 3eqtr2d | ⊢ ( 𝜑  →  ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 ) )  =  ( 𝑃  −  ( 𝑄  +  2 ) ) ) | 
						
							| 272 | 266 271 | eqtr4d | ⊢ ( 𝜑  →  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 ) )  =  ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 ) ) ) | 
						
							| 273 |  | ccatopth | ⊢ ( ( ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  ∈  Word  ( 𝐼  ×  2o ) )  ∧  ( ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) )  ∧  ( ♯ ‘ ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 ) )  =  ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 ) ) )  →  ( ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  ↔  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 )  ∧  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) ) | 
						
							| 274 | 187 143 262 264 272 273 | syl221anc | ⊢ ( 𝜑  →  ( ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ++  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) ) )  =  ( ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  ↔  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 )  ∧  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) ) | 
						
							| 275 | 260 274 | mpbid | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 )  ∧  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 276 | 275 | simpld | ⊢ ( 𝜑  →  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 ) ) | 
						
							| 277 | 275 | simprd | ⊢ ( 𝜑  →  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) | 
						
							| 278 |  | elfzuzb | ⊢ ( ( 𝑃  −  2 )  ∈  ( 0 ... 𝑃 )  ↔  ( ( 𝑃  −  2 )  ∈  ( ℤ≥ ‘ 0 )  ∧  𝑃  ∈  ( ℤ≥ ‘ ( 𝑃  −  2 ) ) ) ) | 
						
							| 279 | 224 248 278 | sylanbrc | ⊢ ( 𝜑  →  ( 𝑃  −  2 )  ∈  ( 0 ... 𝑃 ) ) | 
						
							| 280 |  | elfzuz | ⊢ ( 𝑃  ∈  ( 0 ... ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) )  →  𝑃  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 281 | 14 280 | syl | ⊢ ( 𝜑  →  𝑃  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 282 |  | elfzuzb | ⊢ ( 𝑃  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) )  ↔  ( 𝑃  ∈  ( ℤ≥ ‘ 0 )  ∧  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  ∈  ( ℤ≥ ‘ 𝑃 ) ) ) | 
						
							| 283 | 281 239 282 | sylanbrc | ⊢ ( 𝜑  →  𝑃  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) ) ) | 
						
							| 284 |  | ccatswrd | ⊢ ( ( ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( ( 𝑃  −  2 )  ∈  ( 0 ... 𝑃 )  ∧  𝑃  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) )  ∧  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) ) ) )  →  ( ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) | 
						
							| 285 | 37 279 283 257 284 | syl13anc | ⊢ ( 𝜑  →  ( ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) | 
						
							| 286 | 277 285 | eqtr4d | ⊢ ( 𝜑  →  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 287 |  | swrdcl | ⊢ ( ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 288 | 37 287 | syl | ⊢ ( 𝜑  →  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 )  ∈  Word  ( 𝐼  ×  2o ) ) | 
						
							| 289 |  | s2len | ⊢ ( ♯ ‘ 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 )  =  2 | 
						
							| 290 |  | swrdlen | ⊢ ( ( ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( 𝑃  −  2 )  ∈  ( 0 ... 𝑃 )  ∧  𝑃  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) ) )  →  ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 ) )  =  ( 𝑃  −  ( 𝑃  −  2 ) ) ) | 
						
							| 291 | 37 279 283 290 | syl3anc | ⊢ ( 𝜑  →  ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 ) )  =  ( 𝑃  −  ( 𝑃  −  2 ) ) ) | 
						
							| 292 |  | nncan | ⊢ ( ( 𝑃  ∈  ℂ  ∧  2  ∈  ℂ )  →  ( 𝑃  −  ( 𝑃  −  2 ) )  =  2 ) | 
						
							| 293 | 83 74 292 | sylancl | ⊢ ( 𝜑  →  ( 𝑃  −  ( 𝑃  −  2 ) )  =  2 ) | 
						
							| 294 | 291 293 | eqtr2d | ⊢ ( 𝜑  →  2  =  ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 ) ) ) | 
						
							| 295 | 289 294 | eqtrid | ⊢ ( 𝜑  →  ( ♯ ‘ 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 )  =  ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 ) ) ) | 
						
							| 296 |  | ccatopth | ⊢ ( ( ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ∈  Word  ( 𝐼  ×  2o )  ∧  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) )  ∧  ( ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) )  ∧  ( ♯ ‘ 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 )  =  ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 ) ) )  →  ( ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  ↔  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 )  ∧  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) ) | 
						
							| 297 | 123 125 288 232 295 296 | syl221anc | ⊢ ( 𝜑  →  ( ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  ↔  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 )  ∧  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) ) | 
						
							| 298 | 286 297 | mpbid | ⊢ ( 𝜑  →  ( 〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 )  ∧  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 299 | 298 | simprd | ⊢ ( 𝜑  →  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 )  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) | 
						
							| 300 | 276 299 | oveq12d | ⊢ ( 𝜑  →  ( ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  𝑃 〉 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 301 | 234 300 | eqtr3d | ⊢ ( 𝜑  →  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 )  =  ( ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 302 | 301 | oveq2d | ⊢ ( 𝜑  →  ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) ) | 
						
							| 303 |  | ccatass | ⊢ ( ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 )  ∈  Word  ( 𝐼  ×  2o ) )  →  ( ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 ) )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  =  ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) ) | 
						
							| 304 | 39 262 232 303 | syl3anc | ⊢ ( 𝜑  →  ( ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 ) )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  =  ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) ) | 
						
							| 305 | 302 304 | eqtr4d | ⊢ ( 𝜑  →  ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( ( 𝐴 ‘ 𝐾 )  substr  〈 ( 𝑄  +  2 ) ,  ( ♯ ‘ ( 𝐴 ‘ 𝐾 ) ) 〉 ) )  =  ( ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 ) )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 306 |  | ccatpfx | ⊢ ( ( ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o )  ∧  𝑄  ∈  ( 0 ... ( 𝑃  −  2 ) )  ∧  ( 𝑃  −  2 )  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) ) )  →  ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 ) )  =  ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) ) ) | 
						
							| 307 | 37 237 252 306 | syl3anc | ⊢ ( 𝜑  →  ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 ) )  =  ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) ) ) | 
						
							| 308 | 307 | oveq1d | ⊢ ( 𝜑  →  ( ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑄 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑄 ,  ( 𝑃  −  2 ) 〉 ) )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  =  ( ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 309 | 23 305 308 | 3eqtrd | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝐶 )  =  ( ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 310 |  | ccatrid | ⊢ ( ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) )  ∈  Word  ( 𝐼  ×  2o )  →  ( ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) )  ++  ∅ )  =  ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) ) ) | 
						
							| 311 | 230 310 | syl | ⊢ ( 𝜑  →  ( ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) )  ++  ∅ )  =  ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) ) ) | 
						
							| 312 | 311 | oveq1d | ⊢ ( 𝜑  →  ( ( ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) )  ++  ∅ )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  =  ( ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 313 | 309 312 | eqtr4d | ⊢ ( 𝜑  →  ( 𝑆 ‘ 𝐶 )  =  ( ( ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) )  ++  ∅ )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 314 |  | pfxlen | ⊢ ( ( ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( 𝑃  −  2 )  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) ) )  →  ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) ) )  =  ( 𝑃  −  2 ) ) | 
						
							| 315 | 37 252 314 | syl2anc | ⊢ ( 𝜑  →  ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) ) )  =  ( 𝑃  −  2 ) ) | 
						
							| 316 | 315 | eqcomd | ⊢ ( 𝜑  →  ( 𝑃  −  2 )  =  ( ♯ ‘ ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) ) ) ) | 
						
							| 317 | 172 | oveq2i | ⊢ ( ( 𝑃  −  2 )  +  ( ♯ ‘ ∅ ) )  =  ( ( 𝑃  −  2 )  +  0 ) | 
						
							| 318 | 81 | zcnd | ⊢ ( 𝜑  →  ( 𝑃  −  2 )  ∈  ℂ ) | 
						
							| 319 | 318 | addridd | ⊢ ( 𝜑  →  ( ( 𝑃  −  2 )  +  0 )  =  ( 𝑃  −  2 ) ) | 
						
							| 320 | 317 319 | eqtr2id | ⊢ ( 𝜑  →  ( 𝑃  −  2 )  =  ( ( 𝑃  −  2 )  +  ( ♯ ‘ ∅ ) ) ) | 
						
							| 321 | 230 102 232 123 313 316 320 | splval2 | ⊢ ( 𝜑  →  ( ( 𝑆 ‘ 𝐶 )  splice  〈 ( 𝑃  −  2 ) ,  ( 𝑃  −  2 ) ,  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 〉 )  =  ( ( ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) )  ++  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 322 | 298 | simpld | ⊢ ( 𝜑  →  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉  =  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 ) ) | 
						
							| 323 | 322 | oveq2d | ⊢ ( 𝜑  →  ( ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) )  ++  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 )  =  ( ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 ) ) ) | 
						
							| 324 |  | ccatpfx | ⊢ ( ( ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o )  ∧  ( 𝑃  −  2 )  ∈  ( 0 ... 𝑃 )  ∧  𝑃  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) ) )  →  ( ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 ) )  =  ( ( 𝐵 ‘ 𝐿 )  prefix  𝑃 ) ) | 
						
							| 325 | 37 279 283 324 | syl3anc | ⊢ ( 𝜑  →  ( ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 ( 𝑃  −  2 ) ,  𝑃 〉 ) )  =  ( ( 𝐵 ‘ 𝐿 )  prefix  𝑃 ) ) | 
						
							| 326 | 323 325 | eqtrd | ⊢ ( 𝜑  →  ( ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) )  ++  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 )  =  ( ( 𝐵 ‘ 𝐿 )  prefix  𝑃 ) ) | 
						
							| 327 | 326 | oveq1d | ⊢ ( 𝜑  →  ( ( ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) )  ++  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  =  ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑃 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) ) ) | 
						
							| 328 |  | ccatpfx | ⊢ ( ( ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o )  ∧  𝑃  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) )  ∧  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) )  ∈  ( 0 ... ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) ) )  →  ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑃 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  =  ( ( 𝐵 ‘ 𝐿 )  prefix  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) ) ) | 
						
							| 329 | 37 283 257 328 | syl3anc | ⊢ ( 𝜑  →  ( ( ( 𝐵 ‘ 𝐿 )  prefix  𝑃 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  =  ( ( 𝐵 ‘ 𝐿 )  prefix  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) ) ) | 
						
							| 330 |  | pfxid | ⊢ ( ( 𝐵 ‘ 𝐿 )  ∈  Word  ( 𝐼  ×  2o )  →  ( ( 𝐵 ‘ 𝐿 )  prefix  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) )  =  ( 𝐵 ‘ 𝐿 ) ) | 
						
							| 331 | 37 330 | syl | ⊢ ( 𝜑  →  ( ( 𝐵 ‘ 𝐿 )  prefix  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) )  =  ( 𝐵 ‘ 𝐿 ) ) | 
						
							| 332 | 327 329 331 | 3eqtrd | ⊢ ( 𝜑  →  ( ( ( ( 𝐵 ‘ 𝐿 )  prefix  ( 𝑃  −  2 ) )  ++  〈“ 𝑈 ( 𝑀 ‘ 𝑈 ) ”〉 )  ++  ( ( 𝐵 ‘ 𝐿 )  substr  〈 𝑃 ,  ( ♯ ‘ ( 𝐵 ‘ 𝐿 ) ) 〉 ) )  =  ( 𝐵 ‘ 𝐿 ) ) | 
						
							| 333 | 228 321 332 | 3eqtrd | ⊢ ( 𝜑  →  ( ( 𝑃  −  2 ) ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) 𝑈 )  =  ( 𝐵 ‘ 𝐿 ) ) | 
						
							| 334 |  | fnovrn | ⊢ ( ( ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) )  Fn  ( ( 0 ... ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) ) )  ×  ( 𝐼  ×  2o ) )  ∧  ( 𝑃  −  2 )  ∈  ( 0 ... ( ♯ ‘ ( 𝑆 ‘ 𝐶 ) ) )  ∧  𝑈  ∈  ( 𝐼  ×  2o ) )  →  ( ( 𝑃  −  2 ) ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) 𝑈 )  ∈  ran  ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) ) | 
						
							| 335 | 219 226 16 334 | syl3anc | ⊢ ( 𝜑  →  ( ( 𝑃  −  2 ) ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) 𝑈 )  ∈  ran  ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) ) | 
						
							| 336 | 333 335 | eqeltrrd | ⊢ ( 𝜑  →  ( 𝐵 ‘ 𝐿 )  ∈  ran  ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) ) | 
						
							| 337 | 222 336 | jca | ⊢ ( 𝜑  →  ( ( 𝐴 ‘ 𝐾 )  ∈  ran  ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) )  ∧  ( 𝐵 ‘ 𝐿 )  ∈  ran  ( 𝑇 ‘ ( 𝑆 ‘ 𝐶 ) ) ) ) |