| Step | Hyp | Ref | Expression | 
						
							| 1 |  | clwlkclwwlkf.c | ⊢ 𝐶  =  { 𝑤  ∈  ( ClWalks ‘ 𝐺 )  ∣  1  ≤  ( ♯ ‘ ( 1st  ‘ 𝑤 ) ) } | 
						
							| 2 |  | clwlkclwwlkf.a | ⊢ 𝐴  =  ( 1st  ‘ 𝑈 ) | 
						
							| 3 |  | clwlkclwwlkf.b | ⊢ 𝐵  =  ( 2nd  ‘ 𝑈 ) | 
						
							| 4 |  | clwlkclwwlkf.d | ⊢ 𝐷  =  ( 1st  ‘ 𝑊 ) | 
						
							| 5 |  | clwlkclwwlkf.e | ⊢ 𝐸  =  ( 2nd  ‘ 𝑊 ) | 
						
							| 6 | 1 2 3 4 5 | clwlkclwwlkf1lem2 | ⊢ ( ( 𝑈  ∈  𝐶  ∧  𝑊  ∈  𝐶  ∧  ( 𝐵  prefix  ( ♯ ‘ 𝐴 ) )  =  ( 𝐸  prefix  ( ♯ ‘ 𝐷 ) ) )  →  ( ( ♯ ‘ 𝐴 )  =  ( ♯ ‘ 𝐷 )  ∧  ∀ 𝑖  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 ) ) ) | 
						
							| 7 |  | simprr | ⊢ ( ( ( 𝑈  ∈  𝐶  ∧  𝑊  ∈  𝐶  ∧  ( 𝐵  prefix  ( ♯ ‘ 𝐴 ) )  =  ( 𝐸  prefix  ( ♯ ‘ 𝐷 ) ) )  ∧  ( ( ♯ ‘ 𝐴 )  =  ( ♯ ‘ 𝐷 )  ∧  ∀ 𝑖  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 ) ) )  →  ∀ 𝑖  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 ) ) | 
						
							| 8 | 1 2 3 | clwlkclwwlkflem | ⊢ ( 𝑈  ∈  𝐶  →  ( 𝐴 ( Walks ‘ 𝐺 ) 𝐵  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  ∧  ( ♯ ‘ 𝐴 )  ∈  ℕ ) ) | 
						
							| 9 | 1 4 5 | clwlkclwwlkflem | ⊢ ( 𝑊  ∈  𝐶  →  ( 𝐷 ( Walks ‘ 𝐺 ) 𝐸  ∧  ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  ∧  ( ♯ ‘ 𝐷 )  ∈  ℕ ) ) | 
						
							| 10 |  | lbfzo0 | ⊢ ( 0  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) )  ↔  ( ♯ ‘ 𝐴 )  ∈  ℕ ) | 
						
							| 11 | 10 | biimpri | ⊢ ( ( ♯ ‘ 𝐴 )  ∈  ℕ  →  0  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ) | 
						
							| 12 | 11 | 3ad2ant3 | ⊢ ( ( 𝐴 ( Walks ‘ 𝐺 ) 𝐵  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  ∧  ( ♯ ‘ 𝐴 )  ∈  ℕ )  →  0  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ) | 
						
							| 13 | 12 | adantr | ⊢ ( ( ( 𝐴 ( Walks ‘ 𝐺 ) 𝐵  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  ∧  ( ♯ ‘ 𝐴 )  ∈  ℕ )  ∧  ( 𝐷 ( Walks ‘ 𝐺 ) 𝐸  ∧  ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  ∧  ( ♯ ‘ 𝐷 )  ∈  ℕ ) )  →  0  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ) | 
						
							| 14 | 13 | adantr | ⊢ ( ( ( ( 𝐴 ( Walks ‘ 𝐺 ) 𝐵  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  ∧  ( ♯ ‘ 𝐴 )  ∈  ℕ )  ∧  ( 𝐷 ( Walks ‘ 𝐺 ) 𝐸  ∧  ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  ∧  ( ♯ ‘ 𝐷 )  ∈  ℕ ) )  ∧  ( ♯ ‘ 𝐴 )  =  ( ♯ ‘ 𝐷 ) )  →  0  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ) | 
						
							| 15 |  | fveq2 | ⊢ ( 𝑖  =  0  →  ( 𝐵 ‘ 𝑖 )  =  ( 𝐵 ‘ 0 ) ) | 
						
							| 16 |  | fveq2 | ⊢ ( 𝑖  =  0  →  ( 𝐸 ‘ 𝑖 )  =  ( 𝐸 ‘ 0 ) ) | 
						
							| 17 | 15 16 | eqeq12d | ⊢ ( 𝑖  =  0  →  ( ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 )  ↔  ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ 0 ) ) ) | 
						
							| 18 | 17 | rspcv | ⊢ ( 0  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) )  →  ( ∀ 𝑖  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 )  →  ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ 0 ) ) ) | 
						
							| 19 | 14 18 | syl | ⊢ ( ( ( ( 𝐴 ( Walks ‘ 𝐺 ) 𝐵  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  ∧  ( ♯ ‘ 𝐴 )  ∈  ℕ )  ∧  ( 𝐷 ( Walks ‘ 𝐺 ) 𝐸  ∧  ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  ∧  ( ♯ ‘ 𝐷 )  ∈  ℕ ) )  ∧  ( ♯ ‘ 𝐴 )  =  ( ♯ ‘ 𝐷 ) )  →  ( ∀ 𝑖  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 )  →  ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ 0 ) ) ) | 
						
							| 20 |  | simpl | ⊢ ( ( ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐵 ‘ 0 )  ∧  ( ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ 0 )  ∧  ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) ) ) )  →  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐵 ‘ 0 ) ) | 
						
							| 21 |  | eqtr | ⊢ ( ( ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ 0 )  ∧  ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) ) )  →  ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) ) ) | 
						
							| 22 | 21 | adantl | ⊢ ( ( ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐵 ‘ 0 )  ∧  ( ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ 0 )  ∧  ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) ) ) )  →  ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) ) ) | 
						
							| 23 | 20 22 | eqtrd | ⊢ ( ( ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐵 ‘ 0 )  ∧  ( ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ 0 )  ∧  ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) ) ) )  →  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) ) ) | 
						
							| 24 | 23 | exp32 | ⊢ ( ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐵 ‘ 0 )  →  ( ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ 0 )  →  ( ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  →  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) ) ) ) ) | 
						
							| 25 | 24 | com23 | ⊢ ( ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐵 ‘ 0 )  →  ( ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  →  ( ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ 0 )  →  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) ) ) ) ) | 
						
							| 26 | 25 | eqcoms | ⊢ ( ( 𝐵 ‘ 0 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  →  ( ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  →  ( ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ 0 )  →  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) ) ) ) ) | 
						
							| 27 | 26 | 3ad2ant2 | ⊢ ( ( 𝐴 ( Walks ‘ 𝐺 ) 𝐵  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  ∧  ( ♯ ‘ 𝐴 )  ∈  ℕ )  →  ( ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  →  ( ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ 0 )  →  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) ) ) ) ) | 
						
							| 28 | 27 | com12 | ⊢ ( ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  →  ( ( 𝐴 ( Walks ‘ 𝐺 ) 𝐵  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  ∧  ( ♯ ‘ 𝐴 )  ∈  ℕ )  →  ( ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ 0 )  →  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) ) ) ) ) | 
						
							| 29 | 28 | 3ad2ant2 | ⊢ ( ( 𝐷 ( Walks ‘ 𝐺 ) 𝐸  ∧  ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  ∧  ( ♯ ‘ 𝐷 )  ∈  ℕ )  →  ( ( 𝐴 ( Walks ‘ 𝐺 ) 𝐵  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  ∧  ( ♯ ‘ 𝐴 )  ∈  ℕ )  →  ( ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ 0 )  →  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) ) ) ) ) | 
						
							| 30 | 29 | impcom | ⊢ ( ( ( 𝐴 ( Walks ‘ 𝐺 ) 𝐵  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  ∧  ( ♯ ‘ 𝐴 )  ∈  ℕ )  ∧  ( 𝐷 ( Walks ‘ 𝐺 ) 𝐸  ∧  ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  ∧  ( ♯ ‘ 𝐷 )  ∈  ℕ ) )  →  ( ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ 0 )  →  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) ) ) ) | 
						
							| 31 | 30 | adantr | ⊢ ( ( ( ( 𝐴 ( Walks ‘ 𝐺 ) 𝐵  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  ∧  ( ♯ ‘ 𝐴 )  ∈  ℕ )  ∧  ( 𝐷 ( Walks ‘ 𝐺 ) 𝐸  ∧  ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  ∧  ( ♯ ‘ 𝐷 )  ∈  ℕ ) )  ∧  ( ♯ ‘ 𝐴 )  =  ( ♯ ‘ 𝐷 ) )  →  ( ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ 0 )  →  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) ) ) ) | 
						
							| 32 | 31 | imp | ⊢ ( ( ( ( ( 𝐴 ( Walks ‘ 𝐺 ) 𝐵  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  ∧  ( ♯ ‘ 𝐴 )  ∈  ℕ )  ∧  ( 𝐷 ( Walks ‘ 𝐺 ) 𝐸  ∧  ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  ∧  ( ♯ ‘ 𝐷 )  ∈  ℕ ) )  ∧  ( ♯ ‘ 𝐴 )  =  ( ♯ ‘ 𝐷 ) )  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ 0 ) )  →  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) ) ) | 
						
							| 33 |  | fveq2 | ⊢ ( ( ♯ ‘ 𝐷 )  =  ( ♯ ‘ 𝐴 )  →  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐴 ) ) ) | 
						
							| 34 | 33 | eqcoms | ⊢ ( ( ♯ ‘ 𝐴 )  =  ( ♯ ‘ 𝐷 )  →  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐴 ) ) ) | 
						
							| 35 | 34 | adantl | ⊢ ( ( ( ( 𝐴 ( Walks ‘ 𝐺 ) 𝐵  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  ∧  ( ♯ ‘ 𝐴 )  ∈  ℕ )  ∧  ( 𝐷 ( Walks ‘ 𝐺 ) 𝐸  ∧  ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  ∧  ( ♯ ‘ 𝐷 )  ∈  ℕ ) )  ∧  ( ♯ ‘ 𝐴 )  =  ( ♯ ‘ 𝐷 ) )  →  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐴 ) ) ) | 
						
							| 36 | 35 | adantr | ⊢ ( ( ( ( ( 𝐴 ( Walks ‘ 𝐺 ) 𝐵  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  ∧  ( ♯ ‘ 𝐴 )  ∈  ℕ )  ∧  ( 𝐷 ( Walks ‘ 𝐺 ) 𝐸  ∧  ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  ∧  ( ♯ ‘ 𝐷 )  ∈  ℕ ) )  ∧  ( ♯ ‘ 𝐴 )  =  ( ♯ ‘ 𝐷 ) )  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ 0 ) )  →  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐴 ) ) ) | 
						
							| 37 | 32 36 | eqtrd | ⊢ ( ( ( ( ( 𝐴 ( Walks ‘ 𝐺 ) 𝐵  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  ∧  ( ♯ ‘ 𝐴 )  ∈  ℕ )  ∧  ( 𝐷 ( Walks ‘ 𝐺 ) 𝐸  ∧  ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  ∧  ( ♯ ‘ 𝐷 )  ∈  ℕ ) )  ∧  ( ♯ ‘ 𝐴 )  =  ( ♯ ‘ 𝐷 ) )  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ 0 ) )  →  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐴 ) ) ) | 
						
							| 38 | 37 | ex | ⊢ ( ( ( ( 𝐴 ( Walks ‘ 𝐺 ) 𝐵  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  ∧  ( ♯ ‘ 𝐴 )  ∈  ℕ )  ∧  ( 𝐷 ( Walks ‘ 𝐺 ) 𝐸  ∧  ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  ∧  ( ♯ ‘ 𝐷 )  ∈  ℕ ) )  ∧  ( ♯ ‘ 𝐴 )  =  ( ♯ ‘ 𝐷 ) )  →  ( ( 𝐵 ‘ 0 )  =  ( 𝐸 ‘ 0 )  →  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐴 ) ) ) ) | 
						
							| 39 | 19 38 | syld | ⊢ ( ( ( ( 𝐴 ( Walks ‘ 𝐺 ) 𝐵  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  ∧  ( ♯ ‘ 𝐴 )  ∈  ℕ )  ∧  ( 𝐷 ( Walks ‘ 𝐺 ) 𝐸  ∧  ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  ∧  ( ♯ ‘ 𝐷 )  ∈  ℕ ) )  ∧  ( ♯ ‘ 𝐴 )  =  ( ♯ ‘ 𝐷 ) )  →  ( ∀ 𝑖  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 )  →  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐴 ) ) ) ) | 
						
							| 40 | 39 | ex | ⊢ ( ( ( 𝐴 ( Walks ‘ 𝐺 ) 𝐵  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  ∧  ( ♯ ‘ 𝐴 )  ∈  ℕ )  ∧  ( 𝐷 ( Walks ‘ 𝐺 ) 𝐸  ∧  ( 𝐸 ‘ 0 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐷 ) )  ∧  ( ♯ ‘ 𝐷 )  ∈  ℕ ) )  →  ( ( ♯ ‘ 𝐴 )  =  ( ♯ ‘ 𝐷 )  →  ( ∀ 𝑖  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 )  →  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐴 ) ) ) ) ) | 
						
							| 41 | 8 9 40 | syl2an | ⊢ ( ( 𝑈  ∈  𝐶  ∧  𝑊  ∈  𝐶 )  →  ( ( ♯ ‘ 𝐴 )  =  ( ♯ ‘ 𝐷 )  →  ( ∀ 𝑖  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 )  →  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐴 ) ) ) ) ) | 
						
							| 42 | 41 | impd | ⊢ ( ( 𝑈  ∈  𝐶  ∧  𝑊  ∈  𝐶 )  →  ( ( ( ♯ ‘ 𝐴 )  =  ( ♯ ‘ 𝐷 )  ∧  ∀ 𝑖  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 ) )  →  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐴 ) ) ) ) | 
						
							| 43 | 42 | 3adant3 | ⊢ ( ( 𝑈  ∈  𝐶  ∧  𝑊  ∈  𝐶  ∧  ( 𝐵  prefix  ( ♯ ‘ 𝐴 ) )  =  ( 𝐸  prefix  ( ♯ ‘ 𝐷 ) ) )  →  ( ( ( ♯ ‘ 𝐴 )  =  ( ♯ ‘ 𝐷 )  ∧  ∀ 𝑖  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 ) )  →  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐴 ) ) ) ) | 
						
							| 44 | 43 | imp | ⊢ ( ( ( 𝑈  ∈  𝐶  ∧  𝑊  ∈  𝐶  ∧  ( 𝐵  prefix  ( ♯ ‘ 𝐴 ) )  =  ( 𝐸  prefix  ( ♯ ‘ 𝐷 ) ) )  ∧  ( ( ♯ ‘ 𝐴 )  =  ( ♯ ‘ 𝐷 )  ∧  ∀ 𝑖  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 ) ) )  →  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐴 ) ) ) | 
						
							| 45 | 7 44 | jca | ⊢ ( ( ( 𝑈  ∈  𝐶  ∧  𝑊  ∈  𝐶  ∧  ( 𝐵  prefix  ( ♯ ‘ 𝐴 ) )  =  ( 𝐸  prefix  ( ♯ ‘ 𝐷 ) ) )  ∧  ( ( ♯ ‘ 𝐴 )  =  ( ♯ ‘ 𝐷 )  ∧  ∀ 𝑖  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 ) ) )  →  ( ∀ 𝑖  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 )  ∧  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐴 ) ) ) ) | 
						
							| 46 | 6 45 | mpdan | ⊢ ( ( 𝑈  ∈  𝐶  ∧  𝑊  ∈  𝐶  ∧  ( 𝐵  prefix  ( ♯ ‘ 𝐴 ) )  =  ( 𝐸  prefix  ( ♯ ‘ 𝐷 ) ) )  →  ( ∀ 𝑖  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 )  ∧  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐴 ) ) ) ) | 
						
							| 47 |  | fvex | ⊢ ( ♯ ‘ 𝐴 )  ∈  V | 
						
							| 48 |  | fveq2 | ⊢ ( 𝑖  =  ( ♯ ‘ 𝐴 )  →  ( 𝐵 ‘ 𝑖 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) ) ) | 
						
							| 49 |  | fveq2 | ⊢ ( 𝑖  =  ( ♯ ‘ 𝐴 )  →  ( 𝐸 ‘ 𝑖 )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐴 ) ) ) | 
						
							| 50 | 48 49 | eqeq12d | ⊢ ( 𝑖  =  ( ♯ ‘ 𝐴 )  →  ( ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 )  ↔  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐴 ) ) ) ) | 
						
							| 51 | 50 | ralunsn | ⊢ ( ( ♯ ‘ 𝐴 )  ∈  V  →  ( ∀ 𝑖  ∈  ( ( 0 ..^ ( ♯ ‘ 𝐴 ) )  ∪  { ( ♯ ‘ 𝐴 ) } ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 )  ↔  ( ∀ 𝑖  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 )  ∧  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐴 ) ) ) ) ) | 
						
							| 52 | 47 51 | ax-mp | ⊢ ( ∀ 𝑖  ∈  ( ( 0 ..^ ( ♯ ‘ 𝐴 ) )  ∪  { ( ♯ ‘ 𝐴 ) } ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 )  ↔  ( ∀ 𝑖  ∈  ( 0 ..^ ( ♯ ‘ 𝐴 ) ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 )  ∧  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  =  ( 𝐸 ‘ ( ♯ ‘ 𝐴 ) ) ) ) | 
						
							| 53 | 46 52 | sylibr | ⊢ ( ( 𝑈  ∈  𝐶  ∧  𝑊  ∈  𝐶  ∧  ( 𝐵  prefix  ( ♯ ‘ 𝐴 ) )  =  ( 𝐸  prefix  ( ♯ ‘ 𝐷 ) ) )  →  ∀ 𝑖  ∈  ( ( 0 ..^ ( ♯ ‘ 𝐴 ) )  ∪  { ( ♯ ‘ 𝐴 ) } ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 ) ) | 
						
							| 54 |  | nnnn0 | ⊢ ( ( ♯ ‘ 𝐴 )  ∈  ℕ  →  ( ♯ ‘ 𝐴 )  ∈  ℕ0 ) | 
						
							| 55 |  | elnn0uz | ⊢ ( ( ♯ ‘ 𝐴 )  ∈  ℕ0  ↔  ( ♯ ‘ 𝐴 )  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 56 | 54 55 | sylib | ⊢ ( ( ♯ ‘ 𝐴 )  ∈  ℕ  →  ( ♯ ‘ 𝐴 )  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 57 | 56 | 3ad2ant3 | ⊢ ( ( 𝐴 ( Walks ‘ 𝐺 ) 𝐵  ∧  ( 𝐵 ‘ 0 )  =  ( 𝐵 ‘ ( ♯ ‘ 𝐴 ) )  ∧  ( ♯ ‘ 𝐴 )  ∈  ℕ )  →  ( ♯ ‘ 𝐴 )  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 58 | 8 57 | syl | ⊢ ( 𝑈  ∈  𝐶  →  ( ♯ ‘ 𝐴 )  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 59 | 58 | 3ad2ant1 | ⊢ ( ( 𝑈  ∈  𝐶  ∧  𝑊  ∈  𝐶  ∧  ( 𝐵  prefix  ( ♯ ‘ 𝐴 ) )  =  ( 𝐸  prefix  ( ♯ ‘ 𝐷 ) ) )  →  ( ♯ ‘ 𝐴 )  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 60 |  | fzisfzounsn | ⊢ ( ( ♯ ‘ 𝐴 )  ∈  ( ℤ≥ ‘ 0 )  →  ( 0 ... ( ♯ ‘ 𝐴 ) )  =  ( ( 0 ..^ ( ♯ ‘ 𝐴 ) )  ∪  { ( ♯ ‘ 𝐴 ) } ) ) | 
						
							| 61 | 59 60 | syl | ⊢ ( ( 𝑈  ∈  𝐶  ∧  𝑊  ∈  𝐶  ∧  ( 𝐵  prefix  ( ♯ ‘ 𝐴 ) )  =  ( 𝐸  prefix  ( ♯ ‘ 𝐷 ) ) )  →  ( 0 ... ( ♯ ‘ 𝐴 ) )  =  ( ( 0 ..^ ( ♯ ‘ 𝐴 ) )  ∪  { ( ♯ ‘ 𝐴 ) } ) ) | 
						
							| 62 | 53 61 | raleqtrrdv | ⊢ ( ( 𝑈  ∈  𝐶  ∧  𝑊  ∈  𝐶  ∧  ( 𝐵  prefix  ( ♯ ‘ 𝐴 ) )  =  ( 𝐸  prefix  ( ♯ ‘ 𝐷 ) ) )  →  ∀ 𝑖  ∈  ( 0 ... ( ♯ ‘ 𝐴 ) ) ( 𝐵 ‘ 𝑖 )  =  ( 𝐸 ‘ 𝑖 ) ) |