| 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 |  | eqid |  |-  ( Vtx ` G ) = ( Vtx ` G ) | 
						
							| 5 |  | eqid |  |-  ( Edg ` G ) = ( Edg ` G ) | 
						
							| 6 | 4 5 | clwwlknp |  |-  ( p e. ( N ClWWalksN G ) -> ( ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) /\ A. i e. ( 0 ..^ ( N - 1 ) ) { ( p ` i ) , ( p ` ( i + 1 ) ) } e. ( Edg ` G ) /\ { ( lastS ` p ) , ( p ` 0 ) } e. ( Edg ` G ) ) ) | 
						
							| 7 |  | simpr |  |-  ( ( ( ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) /\ A. i e. ( 0 ..^ ( N - 1 ) ) { ( p ` i ) , ( p ` ( i + 1 ) ) } e. ( Edg ` G ) /\ { ( lastS ` p ) , ( p ` 0 ) } e. ( Edg ` G ) ) /\ N e. NN ) -> N e. NN ) | 
						
							| 8 |  | simpl1 |  |-  ( ( ( ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) /\ A. i e. ( 0 ..^ ( N - 1 ) ) { ( p ` i ) , ( p ` ( i + 1 ) ) } e. ( Edg ` G ) /\ { ( lastS ` p ) , ( p ` 0 ) } e. ( Edg ` G ) ) /\ N e. NN ) -> ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) ) | 
						
							| 9 |  | 3simpc |  |-  ( ( ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) /\ A. i e. ( 0 ..^ ( N - 1 ) ) { ( p ` i ) , ( p ` ( i + 1 ) ) } e. ( Edg ` G ) /\ { ( lastS ` p ) , ( p ` 0 ) } e. ( Edg ` G ) ) -> ( A. i e. ( 0 ..^ ( N - 1 ) ) { ( p ` i ) , ( p ` ( i + 1 ) ) } e. ( Edg ` G ) /\ { ( lastS ` p ) , ( p ` 0 ) } e. ( Edg ` G ) ) ) | 
						
							| 10 | 9 | adantr |  |-  ( ( ( ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) /\ A. i e. ( 0 ..^ ( N - 1 ) ) { ( p ` i ) , ( p ` ( i + 1 ) ) } e. ( Edg ` G ) /\ { ( lastS ` p ) , ( p ` 0 ) } e. ( Edg ` G ) ) /\ N e. NN ) -> ( A. i e. ( 0 ..^ ( N - 1 ) ) { ( p ` i ) , ( p ` ( i + 1 ) ) } e. ( Edg ` G ) /\ { ( lastS ` p ) , ( p ` 0 ) } e. ( Edg ` G ) ) ) | 
						
							| 11 | 1 | clwwlkel |  |-  ( ( N e. NN /\ ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) /\ ( A. i e. ( 0 ..^ ( N - 1 ) ) { ( p ` i ) , ( p ` ( i + 1 ) ) } e. ( Edg ` G ) /\ { ( lastS ` p ) , ( p ` 0 ) } e. ( Edg ` G ) ) ) -> ( p ++ <" ( p ` 0 ) "> ) e. D ) | 
						
							| 12 | 7 8 10 11 | syl3anc |  |-  ( ( ( ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) /\ A. i e. ( 0 ..^ ( N - 1 ) ) { ( p ` i ) , ( p ` ( i + 1 ) ) } e. ( Edg ` G ) /\ { ( lastS ` p ) , ( p ` 0 ) } e. ( Edg ` G ) ) /\ N e. NN ) -> ( p ++ <" ( p ` 0 ) "> ) e. D ) | 
						
							| 13 |  | oveq2 |  |-  ( N = ( # ` p ) -> ( ( p ++ <" ( p ` 0 ) "> ) prefix N ) = ( ( p ++ <" ( p ` 0 ) "> ) prefix ( # ` p ) ) ) | 
						
							| 14 | 13 | eqcoms |  |-  ( ( # ` p ) = N -> ( ( p ++ <" ( p ` 0 ) "> ) prefix N ) = ( ( p ++ <" ( p ` 0 ) "> ) prefix ( # ` p ) ) ) | 
						
							| 15 | 14 | adantl |  |-  ( ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) -> ( ( p ++ <" ( p ` 0 ) "> ) prefix N ) = ( ( p ++ <" ( p ` 0 ) "> ) prefix ( # ` p ) ) ) | 
						
							| 16 | 15 | 3ad2ant1 |  |-  ( ( ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) /\ A. i e. ( 0 ..^ ( N - 1 ) ) { ( p ` i ) , ( p ` ( i + 1 ) ) } e. ( Edg ` G ) /\ { ( lastS ` p ) , ( p ` 0 ) } e. ( Edg ` G ) ) -> ( ( p ++ <" ( p ` 0 ) "> ) prefix N ) = ( ( p ++ <" ( p ` 0 ) "> ) prefix ( # ` p ) ) ) | 
						
							| 17 | 16 | adantr |  |-  ( ( ( ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) /\ A. i e. ( 0 ..^ ( N - 1 ) ) { ( p ` i ) , ( p ` ( i + 1 ) ) } e. ( Edg ` G ) /\ { ( lastS ` p ) , ( p ` 0 ) } e. ( Edg ` G ) ) /\ N e. NN ) -> ( ( p ++ <" ( p ` 0 ) "> ) prefix N ) = ( ( p ++ <" ( p ` 0 ) "> ) prefix ( # ` p ) ) ) | 
						
							| 18 |  | simpll |  |-  ( ( ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) /\ N e. NN ) -> p e. Word ( Vtx ` G ) ) | 
						
							| 19 |  | fstwrdne0 |  |-  ( ( N e. NN /\ ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) ) -> ( p ` 0 ) e. ( Vtx ` G ) ) | 
						
							| 20 | 19 | ancoms |  |-  ( ( ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) /\ N e. NN ) -> ( p ` 0 ) e. ( Vtx ` G ) ) | 
						
							| 21 | 20 | s1cld |  |-  ( ( ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) /\ N e. NN ) -> <" ( p ` 0 ) "> e. Word ( Vtx ` G ) ) | 
						
							| 22 | 18 21 | jca |  |-  ( ( ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) /\ N e. NN ) -> ( p e. Word ( Vtx ` G ) /\ <" ( p ` 0 ) "> e. Word ( Vtx ` G ) ) ) | 
						
							| 23 | 22 | 3ad2antl1 |  |-  ( ( ( ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) /\ A. i e. ( 0 ..^ ( N - 1 ) ) { ( p ` i ) , ( p ` ( i + 1 ) ) } e. ( Edg ` G ) /\ { ( lastS ` p ) , ( p ` 0 ) } e. ( Edg ` G ) ) /\ N e. NN ) -> ( p e. Word ( Vtx ` G ) /\ <" ( p ` 0 ) "> e. Word ( Vtx ` G ) ) ) | 
						
							| 24 |  | pfxccat1 |  |-  ( ( p e. Word ( Vtx ` G ) /\ <" ( p ` 0 ) "> e. Word ( Vtx ` G ) ) -> ( ( p ++ <" ( p ` 0 ) "> ) prefix ( # ` p ) ) = p ) | 
						
							| 25 | 23 24 | syl |  |-  ( ( ( ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) /\ A. i e. ( 0 ..^ ( N - 1 ) ) { ( p ` i ) , ( p ` ( i + 1 ) ) } e. ( Edg ` G ) /\ { ( lastS ` p ) , ( p ` 0 ) } e. ( Edg ` G ) ) /\ N e. NN ) -> ( ( p ++ <" ( p ` 0 ) "> ) prefix ( # ` p ) ) = p ) | 
						
							| 26 | 17 25 | eqtr2d |  |-  ( ( ( ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) /\ A. i e. ( 0 ..^ ( N - 1 ) ) { ( p ` i ) , ( p ` ( i + 1 ) ) } e. ( Edg ` G ) /\ { ( lastS ` p ) , ( p ` 0 ) } e. ( Edg ` G ) ) /\ N e. NN ) -> p = ( ( p ++ <" ( p ` 0 ) "> ) prefix N ) ) | 
						
							| 27 | 12 26 | jca |  |-  ( ( ( ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) /\ A. i e. ( 0 ..^ ( N - 1 ) ) { ( p ` i ) , ( p ` ( i + 1 ) ) } e. ( Edg ` G ) /\ { ( lastS ` p ) , ( p ` 0 ) } e. ( Edg ` G ) ) /\ N e. NN ) -> ( ( p ++ <" ( p ` 0 ) "> ) e. D /\ p = ( ( p ++ <" ( p ` 0 ) "> ) prefix N ) ) ) | 
						
							| 28 | 27 | ex |  |-  ( ( ( p e. Word ( Vtx ` G ) /\ ( # ` p ) = N ) /\ A. i e. ( 0 ..^ ( N - 1 ) ) { ( p ` i ) , ( p ` ( i + 1 ) ) } e. ( Edg ` G ) /\ { ( lastS ` p ) , ( p ` 0 ) } e. ( Edg ` G ) ) -> ( N e. NN -> ( ( p ++ <" ( p ` 0 ) "> ) e. D /\ p = ( ( p ++ <" ( p ` 0 ) "> ) prefix N ) ) ) ) | 
						
							| 29 | 6 28 | syl |  |-  ( p e. ( N ClWWalksN G ) -> ( N e. NN -> ( ( p ++ <" ( p ` 0 ) "> ) e. D /\ p = ( ( p ++ <" ( p ` 0 ) "> ) prefix N ) ) ) ) | 
						
							| 30 | 29 | impcom |  |-  ( ( N e. NN /\ p e. ( N ClWWalksN G ) ) -> ( ( p ++ <" ( p ` 0 ) "> ) e. D /\ p = ( ( p ++ <" ( p ` 0 ) "> ) prefix N ) ) ) | 
						
							| 31 |  | oveq1 |  |-  ( x = ( p ++ <" ( p ` 0 ) "> ) -> ( x prefix N ) = ( ( p ++ <" ( p ` 0 ) "> ) prefix N ) ) | 
						
							| 32 | 31 | rspceeqv |  |-  ( ( ( p ++ <" ( p ` 0 ) "> ) e. D /\ p = ( ( p ++ <" ( p ` 0 ) "> ) prefix N ) ) -> E. x e. D p = ( x prefix N ) ) | 
						
							| 33 | 30 32 | syl |  |-  ( ( N e. NN /\ p e. ( N ClWWalksN G ) ) -> E. x e. D p = ( x prefix N ) ) | 
						
							| 34 | 1 2 | clwwlkfv |  |-  ( x e. D -> ( F ` x ) = ( x prefix N ) ) | 
						
							| 35 | 34 | eqeq2d |  |-  ( x e. D -> ( p = ( F ` x ) <-> p = ( x prefix N ) ) ) | 
						
							| 36 | 35 | adantl |  |-  ( ( ( N e. NN /\ p e. ( N ClWWalksN G ) ) /\ x e. D ) -> ( p = ( F ` x ) <-> p = ( x prefix N ) ) ) | 
						
							| 37 | 36 | rexbidva |  |-  ( ( N e. NN /\ p e. ( N ClWWalksN G ) ) -> ( E. x e. D p = ( F ` x ) <-> E. x e. D p = ( x prefix N ) ) ) | 
						
							| 38 | 33 37 | mpbird |  |-  ( ( N e. NN /\ p e. ( N ClWWalksN G ) ) -> E. x e. D p = ( F ` x ) ) | 
						
							| 39 | 38 | ralrimiva |  |-  ( N e. NN -> A. p e. ( N ClWWalksN G ) E. x e. D p = ( F ` x ) ) | 
						
							| 40 |  | dffo3 |  |-  ( F : D -onto-> ( N ClWWalksN G ) <-> ( F : D --> ( N ClWWalksN G ) /\ A. p e. ( N ClWWalksN G ) E. x e. D p = ( F ` x ) ) ) | 
						
							| 41 | 3 39 40 | sylanbrc |  |-  ( N e. NN -> F : D -onto-> ( N ClWWalksN G ) ) |