| Step | Hyp | Ref | Expression | 
						
							| 1 |  | clwwlkf1o.d |  |-  D = { w e. ( N WWalksN G ) | ( lastS ` w ) = ( w ` 0 ) } | 
						
							| 2 |  | clwwlkf1o.f |  |-  F = ( t e. D |-> ( t prefix N ) ) | 
						
							| 3 | 1 2 | clwwlkf |  |-  ( N e. NN -> F : D --> ( N ClWWalksN G ) ) | 
						
							| 4 | 1 2 | clwwlkfv |  |-  ( x e. D -> ( F ` x ) = ( x prefix N ) ) | 
						
							| 5 | 1 2 | clwwlkfv |  |-  ( y e. D -> ( F ` y ) = ( y prefix N ) ) | 
						
							| 6 | 4 5 | eqeqan12d |  |-  ( ( x e. D /\ y e. D ) -> ( ( F ` x ) = ( F ` y ) <-> ( x prefix N ) = ( y prefix N ) ) ) | 
						
							| 7 | 6 | adantl |  |-  ( ( N e. NN /\ ( x e. D /\ y e. D ) ) -> ( ( F ` x ) = ( F ` y ) <-> ( x prefix N ) = ( y prefix N ) ) ) | 
						
							| 8 |  | fveq2 |  |-  ( w = x -> ( lastS ` w ) = ( lastS ` x ) ) | 
						
							| 9 |  | fveq1 |  |-  ( w = x -> ( w ` 0 ) = ( x ` 0 ) ) | 
						
							| 10 | 8 9 | eqeq12d |  |-  ( w = x -> ( ( lastS ` w ) = ( w ` 0 ) <-> ( lastS ` x ) = ( x ` 0 ) ) ) | 
						
							| 11 | 10 1 | elrab2 |  |-  ( x e. D <-> ( x e. ( N WWalksN G ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) | 
						
							| 12 |  | fveq2 |  |-  ( w = y -> ( lastS ` w ) = ( lastS ` y ) ) | 
						
							| 13 |  | fveq1 |  |-  ( w = y -> ( w ` 0 ) = ( y ` 0 ) ) | 
						
							| 14 | 12 13 | eqeq12d |  |-  ( w = y -> ( ( lastS ` w ) = ( w ` 0 ) <-> ( lastS ` y ) = ( y ` 0 ) ) ) | 
						
							| 15 | 14 1 | elrab2 |  |-  ( y e. D <-> ( y e. ( N WWalksN G ) /\ ( lastS ` y ) = ( y ` 0 ) ) ) | 
						
							| 16 | 11 15 | anbi12i |  |-  ( ( x e. D /\ y e. D ) <-> ( ( x e. ( N WWalksN G ) /\ ( lastS ` x ) = ( x ` 0 ) ) /\ ( y e. ( N WWalksN G ) /\ ( lastS ` y ) = ( y ` 0 ) ) ) ) | 
						
							| 17 |  | eqid |  |-  ( Vtx ` G ) = ( Vtx ` G ) | 
						
							| 18 |  | eqid |  |-  ( Edg ` G ) = ( Edg ` G ) | 
						
							| 19 | 17 18 | wwlknp |  |-  ( x e. ( N WWalksN G ) -> ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) /\ A. i e. ( 0 ..^ N ) { ( x ` i ) , ( x ` ( i + 1 ) ) } e. ( Edg ` G ) ) ) | 
						
							| 20 | 17 18 | wwlknp |  |-  ( y e. ( N WWalksN G ) -> ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) /\ A. i e. ( 0 ..^ N ) { ( y ` i ) , ( y ` ( i + 1 ) ) } e. ( Edg ` G ) ) ) | 
						
							| 21 |  | simprlr |  |-  ( ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) -> ( # ` x ) = ( N + 1 ) ) | 
						
							| 22 |  | simpllr |  |-  ( ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) -> ( # ` y ) = ( N + 1 ) ) | 
						
							| 23 | 21 22 | eqtr4d |  |-  ( ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) -> ( # ` x ) = ( # ` y ) ) | 
						
							| 24 | 23 | ad2antlr |  |-  ( ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) /\ ( x prefix N ) = ( y prefix N ) ) -> ( # ` x ) = ( # ` y ) ) | 
						
							| 25 |  | nncn |  |-  ( N e. NN -> N e. CC ) | 
						
							| 26 |  | ax-1cn |  |-  1 e. CC | 
						
							| 27 |  | pncan |  |-  ( ( N e. CC /\ 1 e. CC ) -> ( ( N + 1 ) - 1 ) = N ) | 
						
							| 28 | 27 | eqcomd |  |-  ( ( N e. CC /\ 1 e. CC ) -> N = ( ( N + 1 ) - 1 ) ) | 
						
							| 29 | 25 26 28 | sylancl |  |-  ( N e. NN -> N = ( ( N + 1 ) - 1 ) ) | 
						
							| 30 |  | oveq1 |  |-  ( ( # ` x ) = ( N + 1 ) -> ( ( # ` x ) - 1 ) = ( ( N + 1 ) - 1 ) ) | 
						
							| 31 | 30 | eqcomd |  |-  ( ( # ` x ) = ( N + 1 ) -> ( ( N + 1 ) - 1 ) = ( ( # ` x ) - 1 ) ) | 
						
							| 32 | 29 31 | sylan9eqr |  |-  ( ( ( # ` x ) = ( N + 1 ) /\ N e. NN ) -> N = ( ( # ` x ) - 1 ) ) | 
						
							| 33 | 32 | oveq2d |  |-  ( ( ( # ` x ) = ( N + 1 ) /\ N e. NN ) -> ( x prefix N ) = ( x prefix ( ( # ` x ) - 1 ) ) ) | 
						
							| 34 | 32 | oveq2d |  |-  ( ( ( # ` x ) = ( N + 1 ) /\ N e. NN ) -> ( y prefix N ) = ( y prefix ( ( # ` x ) - 1 ) ) ) | 
						
							| 35 | 33 34 | eqeq12d |  |-  ( ( ( # ` x ) = ( N + 1 ) /\ N e. NN ) -> ( ( x prefix N ) = ( y prefix N ) <-> ( x prefix ( ( # ` x ) - 1 ) ) = ( y prefix ( ( # ` x ) - 1 ) ) ) ) | 
						
							| 36 | 35 | ex |  |-  ( ( # ` x ) = ( N + 1 ) -> ( N e. NN -> ( ( x prefix N ) = ( y prefix N ) <-> ( x prefix ( ( # ` x ) - 1 ) ) = ( y prefix ( ( # ` x ) - 1 ) ) ) ) ) | 
						
							| 37 | 36 | ad2antlr |  |-  ( ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) -> ( N e. NN -> ( ( x prefix N ) = ( y prefix N ) <-> ( x prefix ( ( # ` x ) - 1 ) ) = ( y prefix ( ( # ` x ) - 1 ) ) ) ) ) | 
						
							| 38 | 37 | adantl |  |-  ( ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) -> ( N e. NN -> ( ( x prefix N ) = ( y prefix N ) <-> ( x prefix ( ( # ` x ) - 1 ) ) = ( y prefix ( ( # ` x ) - 1 ) ) ) ) ) | 
						
							| 39 | 38 | impcom |  |-  ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) -> ( ( x prefix N ) = ( y prefix N ) <-> ( x prefix ( ( # ` x ) - 1 ) ) = ( y prefix ( ( # ` x ) - 1 ) ) ) ) | 
						
							| 40 | 39 | biimpa |  |-  ( ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) /\ ( x prefix N ) = ( y prefix N ) ) -> ( x prefix ( ( # ` x ) - 1 ) ) = ( y prefix ( ( # ` x ) - 1 ) ) ) | 
						
							| 41 |  | simpll |  |-  ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) -> y e. Word ( Vtx ` G ) ) | 
						
							| 42 |  | simpll |  |-  ( ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) -> x e. Word ( Vtx ` G ) ) | 
						
							| 43 | 41 42 | anim12ci |  |-  ( ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) -> ( x e. Word ( Vtx ` G ) /\ y e. Word ( Vtx ` G ) ) ) | 
						
							| 44 | 43 | adantl |  |-  ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) -> ( x e. Word ( Vtx ` G ) /\ y e. Word ( Vtx ` G ) ) ) | 
						
							| 45 |  | nnnn0 |  |-  ( N e. NN -> N e. NN0 ) | 
						
							| 46 |  | 0nn0 |  |-  0 e. NN0 | 
						
							| 47 | 45 46 | jctil |  |-  ( N e. NN -> ( 0 e. NN0 /\ N e. NN0 ) ) | 
						
							| 48 | 47 | adantr |  |-  ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) -> ( 0 e. NN0 /\ N e. NN0 ) ) | 
						
							| 49 |  | nnre |  |-  ( N e. NN -> N e. RR ) | 
						
							| 50 | 49 | lep1d |  |-  ( N e. NN -> N <_ ( N + 1 ) ) | 
						
							| 51 |  | breq2 |  |-  ( ( # ` x ) = ( N + 1 ) -> ( N <_ ( # ` x ) <-> N <_ ( N + 1 ) ) ) | 
						
							| 52 | 50 51 | imbitrrid |  |-  ( ( # ` x ) = ( N + 1 ) -> ( N e. NN -> N <_ ( # ` x ) ) ) | 
						
							| 53 | 52 | ad2antlr |  |-  ( ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) -> ( N e. NN -> N <_ ( # ` x ) ) ) | 
						
							| 54 | 53 | adantl |  |-  ( ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) -> ( N e. NN -> N <_ ( # ` x ) ) ) | 
						
							| 55 | 54 | impcom |  |-  ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) -> N <_ ( # ` x ) ) | 
						
							| 56 |  | breq2 |  |-  ( ( # ` y ) = ( N + 1 ) -> ( N <_ ( # ` y ) <-> N <_ ( N + 1 ) ) ) | 
						
							| 57 | 50 56 | imbitrrid |  |-  ( ( # ` y ) = ( N + 1 ) -> ( N e. NN -> N <_ ( # ` y ) ) ) | 
						
							| 58 | 57 | ad2antlr |  |-  ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) -> ( N e. NN -> N <_ ( # ` y ) ) ) | 
						
							| 59 | 58 | adantr |  |-  ( ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) -> ( N e. NN -> N <_ ( # ` y ) ) ) | 
						
							| 60 | 59 | impcom |  |-  ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) -> N <_ ( # ` y ) ) | 
						
							| 61 |  | pfxval |  |-  ( ( x e. Word ( Vtx ` G ) /\ N e. NN0 ) -> ( x prefix N ) = ( x substr <. 0 , N >. ) ) | 
						
							| 62 | 61 | ad2ant2rl |  |-  ( ( ( x e. Word ( Vtx ` G ) /\ y e. Word ( Vtx ` G ) ) /\ ( 0 e. NN0 /\ N e. NN0 ) ) -> ( x prefix N ) = ( x substr <. 0 , N >. ) ) | 
						
							| 63 |  | pfxval |  |-  ( ( y e. Word ( Vtx ` G ) /\ N e. NN0 ) -> ( y prefix N ) = ( y substr <. 0 , N >. ) ) | 
						
							| 64 | 63 | ad2ant2l |  |-  ( ( ( x e. Word ( Vtx ` G ) /\ y e. Word ( Vtx ` G ) ) /\ ( 0 e. NN0 /\ N e. NN0 ) ) -> ( y prefix N ) = ( y substr <. 0 , N >. ) ) | 
						
							| 65 | 62 64 | eqeq12d |  |-  ( ( ( x e. Word ( Vtx ` G ) /\ y e. Word ( Vtx ` G ) ) /\ ( 0 e. NN0 /\ N e. NN0 ) ) -> ( ( x prefix N ) = ( y prefix N ) <-> ( x substr <. 0 , N >. ) = ( y substr <. 0 , N >. ) ) ) | 
						
							| 66 | 65 | 3adant3 |  |-  ( ( ( x e. Word ( Vtx ` G ) /\ y e. Word ( Vtx ` G ) ) /\ ( 0 e. NN0 /\ N e. NN0 ) /\ ( N <_ ( # ` x ) /\ N <_ ( # ` y ) ) ) -> ( ( x prefix N ) = ( y prefix N ) <-> ( x substr <. 0 , N >. ) = ( y substr <. 0 , N >. ) ) ) | 
						
							| 67 |  | swrdspsleq |  |-  ( ( ( x e. Word ( Vtx ` G ) /\ y e. Word ( Vtx ` G ) ) /\ ( 0 e. NN0 /\ N e. NN0 ) /\ ( N <_ ( # ` x ) /\ N <_ ( # ` y ) ) ) -> ( ( x substr <. 0 , N >. ) = ( y substr <. 0 , N >. ) <-> A. i e. ( 0 ..^ N ) ( x ` i ) = ( y ` i ) ) ) | 
						
							| 68 | 66 67 | bitrd |  |-  ( ( ( x e. Word ( Vtx ` G ) /\ y e. Word ( Vtx ` G ) ) /\ ( 0 e. NN0 /\ N e. NN0 ) /\ ( N <_ ( # ` x ) /\ N <_ ( # ` y ) ) ) -> ( ( x prefix N ) = ( y prefix N ) <-> A. i e. ( 0 ..^ N ) ( x ` i ) = ( y ` i ) ) ) | 
						
							| 69 | 44 48 55 60 68 | syl112anc |  |-  ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) -> ( ( x prefix N ) = ( y prefix N ) <-> A. i e. ( 0 ..^ N ) ( x ` i ) = ( y ` i ) ) ) | 
						
							| 70 |  | lbfzo0 |  |-  ( 0 e. ( 0 ..^ N ) <-> N e. NN ) | 
						
							| 71 | 70 | biimpri |  |-  ( N e. NN -> 0 e. ( 0 ..^ N ) ) | 
						
							| 72 | 71 | adantr |  |-  ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) -> 0 e. ( 0 ..^ N ) ) | 
						
							| 73 |  | fveq2 |  |-  ( i = 0 -> ( x ` i ) = ( x ` 0 ) ) | 
						
							| 74 |  | fveq2 |  |-  ( i = 0 -> ( y ` i ) = ( y ` 0 ) ) | 
						
							| 75 | 73 74 | eqeq12d |  |-  ( i = 0 -> ( ( x ` i ) = ( y ` i ) <-> ( x ` 0 ) = ( y ` 0 ) ) ) | 
						
							| 76 | 75 | rspcv |  |-  ( 0 e. ( 0 ..^ N ) -> ( A. i e. ( 0 ..^ N ) ( x ` i ) = ( y ` i ) -> ( x ` 0 ) = ( y ` 0 ) ) ) | 
						
							| 77 | 72 76 | syl |  |-  ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) -> ( A. i e. ( 0 ..^ N ) ( x ` i ) = ( y ` i ) -> ( x ` 0 ) = ( y ` 0 ) ) ) | 
						
							| 78 | 69 77 | sylbid |  |-  ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) -> ( ( x prefix N ) = ( y prefix N ) -> ( x ` 0 ) = ( y ` 0 ) ) ) | 
						
							| 79 | 78 | imp |  |-  ( ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) /\ ( x prefix N ) = ( y prefix N ) ) -> ( x ` 0 ) = ( y ` 0 ) ) | 
						
							| 80 |  | simpr |  |-  ( ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) -> ( lastS ` x ) = ( x ` 0 ) ) | 
						
							| 81 |  | simpr |  |-  ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) -> ( lastS ` y ) = ( y ` 0 ) ) | 
						
							| 82 | 80 81 | eqeqan12rd |  |-  ( ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) -> ( ( lastS ` x ) = ( lastS ` y ) <-> ( x ` 0 ) = ( y ` 0 ) ) ) | 
						
							| 83 | 82 | ad2antlr |  |-  ( ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) /\ ( x prefix N ) = ( y prefix N ) ) -> ( ( lastS ` x ) = ( lastS ` y ) <-> ( x ` 0 ) = ( y ` 0 ) ) ) | 
						
							| 84 | 79 83 | mpbird |  |-  ( ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) /\ ( x prefix N ) = ( y prefix N ) ) -> ( lastS ` x ) = ( lastS ` y ) ) | 
						
							| 85 | 24 40 84 | jca32 |  |-  ( ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) /\ ( x prefix N ) = ( y prefix N ) ) -> ( ( # ` x ) = ( # ` y ) /\ ( ( x prefix ( ( # ` x ) - 1 ) ) = ( y prefix ( ( # ` x ) - 1 ) ) /\ ( lastS ` x ) = ( lastS ` y ) ) ) ) | 
						
							| 86 | 42 | adantl |  |-  ( ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) -> x e. Word ( Vtx ` G ) ) | 
						
							| 87 | 86 | adantl |  |-  ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) -> x e. Word ( Vtx ` G ) ) | 
						
							| 88 | 41 | adantr |  |-  ( ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) -> y e. Word ( Vtx ` G ) ) | 
						
							| 89 | 88 | adantl |  |-  ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) -> y e. Word ( Vtx ` G ) ) | 
						
							| 90 |  | 1red |  |-  ( N e. NN -> 1 e. RR ) | 
						
							| 91 |  | nngt0 |  |-  ( N e. NN -> 0 < N ) | 
						
							| 92 |  | 0lt1 |  |-  0 < 1 | 
						
							| 93 | 92 | a1i |  |-  ( N e. NN -> 0 < 1 ) | 
						
							| 94 | 49 90 91 93 | addgt0d |  |-  ( N e. NN -> 0 < ( N + 1 ) ) | 
						
							| 95 |  | breq2 |  |-  ( ( # ` x ) = ( N + 1 ) -> ( 0 < ( # ` x ) <-> 0 < ( N + 1 ) ) ) | 
						
							| 96 | 94 95 | imbitrrid |  |-  ( ( # ` x ) = ( N + 1 ) -> ( N e. NN -> 0 < ( # ` x ) ) ) | 
						
							| 97 | 96 | ad2antlr |  |-  ( ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) -> ( N e. NN -> 0 < ( # ` x ) ) ) | 
						
							| 98 | 97 | adantl |  |-  ( ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) -> ( N e. NN -> 0 < ( # ` x ) ) ) | 
						
							| 99 | 98 | impcom |  |-  ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) -> 0 < ( # ` x ) ) | 
						
							| 100 | 87 89 99 | 3jca |  |-  ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) -> ( x e. Word ( Vtx ` G ) /\ y e. Word ( Vtx ` G ) /\ 0 < ( # ` x ) ) ) | 
						
							| 101 | 100 | adantr |  |-  ( ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) /\ ( x prefix N ) = ( y prefix N ) ) -> ( x e. Word ( Vtx ` G ) /\ y e. Word ( Vtx ` G ) /\ 0 < ( # ` x ) ) ) | 
						
							| 102 |  | pfxsuff1eqwrdeq |  |-  ( ( x e. Word ( Vtx ` G ) /\ y e. Word ( Vtx ` G ) /\ 0 < ( # ` x ) ) -> ( x = y <-> ( ( # ` x ) = ( # ` y ) /\ ( ( x prefix ( ( # ` x ) - 1 ) ) = ( y prefix ( ( # ` x ) - 1 ) ) /\ ( lastS ` x ) = ( lastS ` y ) ) ) ) ) | 
						
							| 103 | 101 102 | syl |  |-  ( ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) /\ ( x prefix N ) = ( y prefix N ) ) -> ( x = y <-> ( ( # ` x ) = ( # ` y ) /\ ( ( x prefix ( ( # ` x ) - 1 ) ) = ( y prefix ( ( # ` x ) - 1 ) ) /\ ( lastS ` x ) = ( lastS ` y ) ) ) ) ) | 
						
							| 104 | 85 103 | mpbird |  |-  ( ( ( N e. NN /\ ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) ) /\ ( x prefix N ) = ( y prefix N ) ) -> x = y ) | 
						
							| 105 | 104 | exp31 |  |-  ( N e. NN -> ( ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) /\ ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) ) -> ( ( x prefix N ) = ( y prefix N ) -> x = y ) ) ) | 
						
							| 106 | 105 | expdcom |  |-  ( ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) /\ ( lastS ` y ) = ( y ` 0 ) ) -> ( ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) -> ( N e. NN -> ( ( x prefix N ) = ( y prefix N ) -> x = y ) ) ) ) | 
						
							| 107 | 106 | ex |  |-  ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) ) -> ( ( lastS ` y ) = ( y ` 0 ) -> ( ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) -> ( N e. NN -> ( ( x prefix N ) = ( y prefix N ) -> x = y ) ) ) ) ) | 
						
							| 108 | 107 | 3adant3 |  |-  ( ( y e. Word ( Vtx ` G ) /\ ( # ` y ) = ( N + 1 ) /\ A. i e. ( 0 ..^ N ) { ( y ` i ) , ( y ` ( i + 1 ) ) } e. ( Edg ` G ) ) -> ( ( lastS ` y ) = ( y ` 0 ) -> ( ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) -> ( N e. NN -> ( ( x prefix N ) = ( y prefix N ) -> x = y ) ) ) ) ) | 
						
							| 109 | 20 108 | syl |  |-  ( y e. ( N WWalksN G ) -> ( ( lastS ` y ) = ( y ` 0 ) -> ( ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) -> ( N e. NN -> ( ( x prefix N ) = ( y prefix N ) -> x = y ) ) ) ) ) | 
						
							| 110 | 109 | imp |  |-  ( ( y e. ( N WWalksN G ) /\ ( lastS ` y ) = ( y ` 0 ) ) -> ( ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) /\ ( lastS ` x ) = ( x ` 0 ) ) -> ( N e. NN -> ( ( x prefix N ) = ( y prefix N ) -> x = y ) ) ) ) | 
						
							| 111 | 110 | expdcom |  |-  ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) ) -> ( ( lastS ` x ) = ( x ` 0 ) -> ( ( y e. ( N WWalksN G ) /\ ( lastS ` y ) = ( y ` 0 ) ) -> ( N e. NN -> ( ( x prefix N ) = ( y prefix N ) -> x = y ) ) ) ) ) | 
						
							| 112 | 111 | 3adant3 |  |-  ( ( x e. Word ( Vtx ` G ) /\ ( # ` x ) = ( N + 1 ) /\ A. i e. ( 0 ..^ N ) { ( x ` i ) , ( x ` ( i + 1 ) ) } e. ( Edg ` G ) ) -> ( ( lastS ` x ) = ( x ` 0 ) -> ( ( y e. ( N WWalksN G ) /\ ( lastS ` y ) = ( y ` 0 ) ) -> ( N e. NN -> ( ( x prefix N ) = ( y prefix N ) -> x = y ) ) ) ) ) | 
						
							| 113 | 19 112 | syl |  |-  ( x e. ( N WWalksN G ) -> ( ( lastS ` x ) = ( x ` 0 ) -> ( ( y e. ( N WWalksN G ) /\ ( lastS ` y ) = ( y ` 0 ) ) -> ( N e. NN -> ( ( x prefix N ) = ( y prefix N ) -> x = y ) ) ) ) ) | 
						
							| 114 | 113 | imp31 |  |-  ( ( ( x e. ( N WWalksN G ) /\ ( lastS ` x ) = ( x ` 0 ) ) /\ ( y e. ( N WWalksN G ) /\ ( lastS ` y ) = ( y ` 0 ) ) ) -> ( N e. NN -> ( ( x prefix N ) = ( y prefix N ) -> x = y ) ) ) | 
						
							| 115 | 114 | com12 |  |-  ( N e. NN -> ( ( ( x e. ( N WWalksN G ) /\ ( lastS ` x ) = ( x ` 0 ) ) /\ ( y e. ( N WWalksN G ) /\ ( lastS ` y ) = ( y ` 0 ) ) ) -> ( ( x prefix N ) = ( y prefix N ) -> x = y ) ) ) | 
						
							| 116 | 16 115 | biimtrid |  |-  ( N e. NN -> ( ( x e. D /\ y e. D ) -> ( ( x prefix N ) = ( y prefix N ) -> x = y ) ) ) | 
						
							| 117 | 116 | imp |  |-  ( ( N e. NN /\ ( x e. D /\ y e. D ) ) -> ( ( x prefix N ) = ( y prefix N ) -> x = y ) ) | 
						
							| 118 | 7 117 | sylbid |  |-  ( ( N e. NN /\ ( x e. D /\ y e. D ) ) -> ( ( F ` x ) = ( F ` y ) -> x = y ) ) | 
						
							| 119 | 118 | ralrimivva |  |-  ( N e. NN -> A. x e. D A. y e. D ( ( F ` x ) = ( F ` y ) -> x = y ) ) | 
						
							| 120 |  | dff13 |  |-  ( F : D -1-1-> ( N ClWWalksN G ) <-> ( F : D --> ( N ClWWalksN G ) /\ A. x e. D A. y e. D ( ( F ` x ) = ( F ` y ) -> x = y ) ) ) | 
						
							| 121 | 3 119 120 | sylanbrc |  |-  ( N e. NN -> F : D -1-1-> ( N ClWWalksN G ) ) |