| Step | Hyp | Ref | Expression | 
						
							| 1 |  | wwlksnextbij0.v |  |-  V = ( Vtx ` G ) | 
						
							| 2 |  | wwlksnextbij0.e |  |-  E = ( Edg ` G ) | 
						
							| 3 |  | wwlksnextbij0.d |  |-  D = { w e. Word V | ( ( # ` w ) = ( N + 2 ) /\ ( w prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` w ) } e. E ) } | 
						
							| 4 |  | wwlksnextbij0.r |  |-  R = { n e. V | { ( lastS ` W ) , n } e. E } | 
						
							| 5 |  | wwlksnextbij0.f |  |-  F = ( t e. D |-> ( lastS ` t ) ) | 
						
							| 6 | 1 2 3 4 5 | wwlksnextfun |  |-  ( N e. NN0 -> F : D --> R ) | 
						
							| 7 |  | fveq2 |  |-  ( t = d -> ( lastS ` t ) = ( lastS ` d ) ) | 
						
							| 8 |  | fvex |  |-  ( lastS ` d ) e. _V | 
						
							| 9 | 7 5 8 | fvmpt |  |-  ( d e. D -> ( F ` d ) = ( lastS ` d ) ) | 
						
							| 10 |  | fveq2 |  |-  ( t = x -> ( lastS ` t ) = ( lastS ` x ) ) | 
						
							| 11 |  | fvex |  |-  ( lastS ` x ) e. _V | 
						
							| 12 | 10 5 11 | fvmpt |  |-  ( x e. D -> ( F ` x ) = ( lastS ` x ) ) | 
						
							| 13 | 9 12 | eqeqan12d |  |-  ( ( d e. D /\ x e. D ) -> ( ( F ` d ) = ( F ` x ) <-> ( lastS ` d ) = ( lastS ` x ) ) ) | 
						
							| 14 | 13 | adantl |  |-  ( ( N e. NN0 /\ ( d e. D /\ x e. D ) ) -> ( ( F ` d ) = ( F ` x ) <-> ( lastS ` d ) = ( lastS ` x ) ) ) | 
						
							| 15 |  | fveqeq2 |  |-  ( w = d -> ( ( # ` w ) = ( N + 2 ) <-> ( # ` d ) = ( N + 2 ) ) ) | 
						
							| 16 |  | oveq1 |  |-  ( w = d -> ( w prefix ( N + 1 ) ) = ( d prefix ( N + 1 ) ) ) | 
						
							| 17 | 16 | eqeq1d |  |-  ( w = d -> ( ( w prefix ( N + 1 ) ) = W <-> ( d prefix ( N + 1 ) ) = W ) ) | 
						
							| 18 |  | fveq2 |  |-  ( w = d -> ( lastS ` w ) = ( lastS ` d ) ) | 
						
							| 19 | 18 | preq2d |  |-  ( w = d -> { ( lastS ` W ) , ( lastS ` w ) } = { ( lastS ` W ) , ( lastS ` d ) } ) | 
						
							| 20 | 19 | eleq1d |  |-  ( w = d -> ( { ( lastS ` W ) , ( lastS ` w ) } e. E <-> { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) | 
						
							| 21 | 15 17 20 | 3anbi123d |  |-  ( w = d -> ( ( ( # ` w ) = ( N + 2 ) /\ ( w prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` w ) } e. E ) <-> ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) ) | 
						
							| 22 | 21 3 | elrab2 |  |-  ( d e. D <-> ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) ) | 
						
							| 23 |  | fveqeq2 |  |-  ( w = x -> ( ( # ` w ) = ( N + 2 ) <-> ( # ` x ) = ( N + 2 ) ) ) | 
						
							| 24 |  | oveq1 |  |-  ( w = x -> ( w prefix ( N + 1 ) ) = ( x prefix ( N + 1 ) ) ) | 
						
							| 25 | 24 | eqeq1d |  |-  ( w = x -> ( ( w prefix ( N + 1 ) ) = W <-> ( x prefix ( N + 1 ) ) = W ) ) | 
						
							| 26 |  | fveq2 |  |-  ( w = x -> ( lastS ` w ) = ( lastS ` x ) ) | 
						
							| 27 | 26 | preq2d |  |-  ( w = x -> { ( lastS ` W ) , ( lastS ` w ) } = { ( lastS ` W ) , ( lastS ` x ) } ) | 
						
							| 28 | 27 | eleq1d |  |-  ( w = x -> ( { ( lastS ` W ) , ( lastS ` w ) } e. E <-> { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) | 
						
							| 29 | 23 25 28 | 3anbi123d |  |-  ( w = x -> ( ( ( # ` w ) = ( N + 2 ) /\ ( w prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` w ) } e. E ) <-> ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) ) | 
						
							| 30 | 29 3 | elrab2 |  |-  ( x e. D <-> ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) ) | 
						
							| 31 |  | eqtr3 |  |-  ( ( ( # ` d ) = ( N + 2 ) /\ ( # ` x ) = ( N + 2 ) ) -> ( # ` d ) = ( # ` x ) ) | 
						
							| 32 | 31 | expcom |  |-  ( ( # ` x ) = ( N + 2 ) -> ( ( # ` d ) = ( N + 2 ) -> ( # ` d ) = ( # ` x ) ) ) | 
						
							| 33 | 32 | 3ad2ant1 |  |-  ( ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) -> ( ( # ` d ) = ( N + 2 ) -> ( # ` d ) = ( # ` x ) ) ) | 
						
							| 34 | 33 | adantl |  |-  ( ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) -> ( ( # ` d ) = ( N + 2 ) -> ( # ` d ) = ( # ` x ) ) ) | 
						
							| 35 | 34 | com12 |  |-  ( ( # ` d ) = ( N + 2 ) -> ( ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) -> ( # ` d ) = ( # ` x ) ) ) | 
						
							| 36 | 35 | 3ad2ant1 |  |-  ( ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) -> ( ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) -> ( # ` d ) = ( # ` x ) ) ) | 
						
							| 37 | 36 | adantl |  |-  ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) -> ( ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) -> ( # ` d ) = ( # ` x ) ) ) | 
						
							| 38 | 37 | imp |  |-  ( ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) /\ ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) ) -> ( # ` d ) = ( # ` x ) ) | 
						
							| 39 | 38 | adantr |  |-  ( ( ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) /\ ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) ) /\ N e. NN0 ) -> ( # ` d ) = ( # ` x ) ) | 
						
							| 40 | 39 | adantr |  |-  ( ( ( ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) /\ ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) ) /\ N e. NN0 ) /\ ( lastS ` d ) = ( lastS ` x ) ) -> ( # ` d ) = ( # ` x ) ) | 
						
							| 41 |  | simpr |  |-  ( ( ( ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) /\ ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) ) /\ N e. NN0 ) /\ ( lastS ` d ) = ( lastS ` x ) ) -> ( lastS ` d ) = ( lastS ` x ) ) | 
						
							| 42 |  | eqtr3 |  |-  ( ( ( d prefix ( N + 1 ) ) = W /\ ( x prefix ( N + 1 ) ) = W ) -> ( d prefix ( N + 1 ) ) = ( x prefix ( N + 1 ) ) ) | 
						
							| 43 |  | 1e2m1 |  |-  1 = ( 2 - 1 ) | 
						
							| 44 | 43 | a1i |  |-  ( N e. NN0 -> 1 = ( 2 - 1 ) ) | 
						
							| 45 | 44 | oveq2d |  |-  ( N e. NN0 -> ( N + 1 ) = ( N + ( 2 - 1 ) ) ) | 
						
							| 46 |  | nn0cn |  |-  ( N e. NN0 -> N e. CC ) | 
						
							| 47 |  | 2cnd |  |-  ( N e. NN0 -> 2 e. CC ) | 
						
							| 48 |  | 1cnd |  |-  ( N e. NN0 -> 1 e. CC ) | 
						
							| 49 | 46 47 48 | addsubassd |  |-  ( N e. NN0 -> ( ( N + 2 ) - 1 ) = ( N + ( 2 - 1 ) ) ) | 
						
							| 50 | 45 49 | eqtr4d |  |-  ( N e. NN0 -> ( N + 1 ) = ( ( N + 2 ) - 1 ) ) | 
						
							| 51 | 50 | adantr |  |-  ( ( N e. NN0 /\ ( # ` d ) = ( N + 2 ) ) -> ( N + 1 ) = ( ( N + 2 ) - 1 ) ) | 
						
							| 52 |  | oveq1 |  |-  ( ( # ` d ) = ( N + 2 ) -> ( ( # ` d ) - 1 ) = ( ( N + 2 ) - 1 ) ) | 
						
							| 53 | 52 | eqeq2d |  |-  ( ( # ` d ) = ( N + 2 ) -> ( ( N + 1 ) = ( ( # ` d ) - 1 ) <-> ( N + 1 ) = ( ( N + 2 ) - 1 ) ) ) | 
						
							| 54 | 53 | adantl |  |-  ( ( N e. NN0 /\ ( # ` d ) = ( N + 2 ) ) -> ( ( N + 1 ) = ( ( # ` d ) - 1 ) <-> ( N + 1 ) = ( ( N + 2 ) - 1 ) ) ) | 
						
							| 55 | 51 54 | mpbird |  |-  ( ( N e. NN0 /\ ( # ` d ) = ( N + 2 ) ) -> ( N + 1 ) = ( ( # ` d ) - 1 ) ) | 
						
							| 56 |  | oveq2 |  |-  ( ( N + 1 ) = ( ( # ` d ) - 1 ) -> ( d prefix ( N + 1 ) ) = ( d prefix ( ( # ` d ) - 1 ) ) ) | 
						
							| 57 |  | oveq2 |  |-  ( ( N + 1 ) = ( ( # ` d ) - 1 ) -> ( x prefix ( N + 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) | 
						
							| 58 | 56 57 | eqeq12d |  |-  ( ( N + 1 ) = ( ( # ` d ) - 1 ) -> ( ( d prefix ( N + 1 ) ) = ( x prefix ( N + 1 ) ) <-> ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) | 
						
							| 59 | 55 58 | syl |  |-  ( ( N e. NN0 /\ ( # ` d ) = ( N + 2 ) ) -> ( ( d prefix ( N + 1 ) ) = ( x prefix ( N + 1 ) ) <-> ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) | 
						
							| 60 | 59 | biimpd |  |-  ( ( N e. NN0 /\ ( # ` d ) = ( N + 2 ) ) -> ( ( d prefix ( N + 1 ) ) = ( x prefix ( N + 1 ) ) -> ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) | 
						
							| 61 | 60 | ex |  |-  ( N e. NN0 -> ( ( # ` d ) = ( N + 2 ) -> ( ( d prefix ( N + 1 ) ) = ( x prefix ( N + 1 ) ) -> ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) ) | 
						
							| 62 | 61 | com13 |  |-  ( ( d prefix ( N + 1 ) ) = ( x prefix ( N + 1 ) ) -> ( ( # ` d ) = ( N + 2 ) -> ( N e. NN0 -> ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) ) | 
						
							| 63 | 42 62 | syl |  |-  ( ( ( d prefix ( N + 1 ) ) = W /\ ( x prefix ( N + 1 ) ) = W ) -> ( ( # ` d ) = ( N + 2 ) -> ( N e. NN0 -> ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) ) | 
						
							| 64 | 63 | ex |  |-  ( ( d prefix ( N + 1 ) ) = W -> ( ( x prefix ( N + 1 ) ) = W -> ( ( # ` d ) = ( N + 2 ) -> ( N e. NN0 -> ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) ) ) | 
						
							| 65 | 64 | com23 |  |-  ( ( d prefix ( N + 1 ) ) = W -> ( ( # ` d ) = ( N + 2 ) -> ( ( x prefix ( N + 1 ) ) = W -> ( N e. NN0 -> ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) ) ) | 
						
							| 66 | 65 | impcom |  |-  ( ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W ) -> ( ( x prefix ( N + 1 ) ) = W -> ( N e. NN0 -> ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) ) | 
						
							| 67 | 66 | com12 |  |-  ( ( x prefix ( N + 1 ) ) = W -> ( ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W ) -> ( N e. NN0 -> ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) ) | 
						
							| 68 | 67 | 3ad2ant2 |  |-  ( ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) -> ( ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W ) -> ( N e. NN0 -> ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) ) | 
						
							| 69 | 68 | adantl |  |-  ( ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) -> ( ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W ) -> ( N e. NN0 -> ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) ) | 
						
							| 70 | 69 | com12 |  |-  ( ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W ) -> ( ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) -> ( N e. NN0 -> ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) ) | 
						
							| 71 | 70 | 3adant3 |  |-  ( ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) -> ( ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) -> ( N e. NN0 -> ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) ) | 
						
							| 72 | 71 | adantl |  |-  ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) -> ( ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) -> ( N e. NN0 -> ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) ) | 
						
							| 73 | 72 | imp31 |  |-  ( ( ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) /\ ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) ) /\ N e. NN0 ) -> ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) | 
						
							| 74 | 73 | adantr |  |-  ( ( ( ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) /\ ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) ) /\ N e. NN0 ) /\ ( lastS ` d ) = ( lastS ` x ) ) -> ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) | 
						
							| 75 |  | simpl |  |-  ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) -> d e. Word V ) | 
						
							| 76 |  | simpl |  |-  ( ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) -> x e. Word V ) | 
						
							| 77 | 75 76 | anim12i |  |-  ( ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) /\ ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) ) -> ( d e. Word V /\ x e. Word V ) ) | 
						
							| 78 | 77 | adantr |  |-  ( ( ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) /\ ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) ) /\ N e. NN0 ) -> ( d e. Word V /\ x e. Word V ) ) | 
						
							| 79 |  | nn0re |  |-  ( N e. NN0 -> N e. RR ) | 
						
							| 80 |  | 2re |  |-  2 e. RR | 
						
							| 81 | 80 | a1i |  |-  ( N e. NN0 -> 2 e. RR ) | 
						
							| 82 |  | nn0ge0 |  |-  ( N e. NN0 -> 0 <_ N ) | 
						
							| 83 |  | 2pos |  |-  0 < 2 | 
						
							| 84 | 83 | a1i |  |-  ( N e. NN0 -> 0 < 2 ) | 
						
							| 85 | 79 81 82 84 | addgegt0d |  |-  ( N e. NN0 -> 0 < ( N + 2 ) ) | 
						
							| 86 | 85 | adantl |  |-  ( ( ( # ` d ) = ( N + 2 ) /\ N e. NN0 ) -> 0 < ( N + 2 ) ) | 
						
							| 87 |  | breq2 |  |-  ( ( # ` d ) = ( N + 2 ) -> ( 0 < ( # ` d ) <-> 0 < ( N + 2 ) ) ) | 
						
							| 88 | 87 | adantr |  |-  ( ( ( # ` d ) = ( N + 2 ) /\ N e. NN0 ) -> ( 0 < ( # ` d ) <-> 0 < ( N + 2 ) ) ) | 
						
							| 89 | 86 88 | mpbird |  |-  ( ( ( # ` d ) = ( N + 2 ) /\ N e. NN0 ) -> 0 < ( # ` d ) ) | 
						
							| 90 |  | hashgt0n0 |  |-  ( ( d e. Word V /\ 0 < ( # ` d ) ) -> d =/= (/) ) | 
						
							| 91 | 89 90 | sylan2 |  |-  ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ N e. NN0 ) ) -> d =/= (/) ) | 
						
							| 92 | 91 | exp32 |  |-  ( d e. Word V -> ( ( # ` d ) = ( N + 2 ) -> ( N e. NN0 -> d =/= (/) ) ) ) | 
						
							| 93 | 92 | com12 |  |-  ( ( # ` d ) = ( N + 2 ) -> ( d e. Word V -> ( N e. NN0 -> d =/= (/) ) ) ) | 
						
							| 94 | 93 | 3ad2ant1 |  |-  ( ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) -> ( d e. Word V -> ( N e. NN0 -> d =/= (/) ) ) ) | 
						
							| 95 | 94 | impcom |  |-  ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) -> ( N e. NN0 -> d =/= (/) ) ) | 
						
							| 96 | 95 | adantr |  |-  ( ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) /\ ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) ) -> ( N e. NN0 -> d =/= (/) ) ) | 
						
							| 97 | 96 | imp |  |-  ( ( ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) /\ ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) ) /\ N e. NN0 ) -> d =/= (/) ) | 
						
							| 98 | 85 | adantl |  |-  ( ( ( # ` x ) = ( N + 2 ) /\ N e. NN0 ) -> 0 < ( N + 2 ) ) | 
						
							| 99 |  | breq2 |  |-  ( ( # ` x ) = ( N + 2 ) -> ( 0 < ( # ` x ) <-> 0 < ( N + 2 ) ) ) | 
						
							| 100 | 99 | adantr |  |-  ( ( ( # ` x ) = ( N + 2 ) /\ N e. NN0 ) -> ( 0 < ( # ` x ) <-> 0 < ( N + 2 ) ) ) | 
						
							| 101 | 98 100 | mpbird |  |-  ( ( ( # ` x ) = ( N + 2 ) /\ N e. NN0 ) -> 0 < ( # ` x ) ) | 
						
							| 102 |  | hashgt0n0 |  |-  ( ( x e. Word V /\ 0 < ( # ` x ) ) -> x =/= (/) ) | 
						
							| 103 | 101 102 | sylan2 |  |-  ( ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ N e. NN0 ) ) -> x =/= (/) ) | 
						
							| 104 | 103 | exp32 |  |-  ( x e. Word V -> ( ( # ` x ) = ( N + 2 ) -> ( N e. NN0 -> x =/= (/) ) ) ) | 
						
							| 105 | 104 | com12 |  |-  ( ( # ` x ) = ( N + 2 ) -> ( x e. Word V -> ( N e. NN0 -> x =/= (/) ) ) ) | 
						
							| 106 | 105 | 3ad2ant1 |  |-  ( ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) -> ( x e. Word V -> ( N e. NN0 -> x =/= (/) ) ) ) | 
						
							| 107 | 106 | impcom |  |-  ( ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) -> ( N e. NN0 -> x =/= (/) ) ) | 
						
							| 108 | 107 | adantl |  |-  ( ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) /\ ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) ) -> ( N e. NN0 -> x =/= (/) ) ) | 
						
							| 109 | 108 | imp |  |-  ( ( ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) /\ ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) ) /\ N e. NN0 ) -> x =/= (/) ) | 
						
							| 110 | 78 97 109 | jca32 |  |-  ( ( ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) /\ ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) ) /\ N e. NN0 ) -> ( ( d e. Word V /\ x e. Word V ) /\ ( d =/= (/) /\ x =/= (/) ) ) ) | 
						
							| 111 | 110 | adantr |  |-  ( ( ( ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) /\ ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) ) /\ N e. NN0 ) /\ ( lastS ` d ) = ( lastS ` x ) ) -> ( ( d e. Word V /\ x e. Word V ) /\ ( d =/= (/) /\ x =/= (/) ) ) ) | 
						
							| 112 |  | simpl |  |-  ( ( d e. Word V /\ x e. Word V ) -> d e. Word V ) | 
						
							| 113 | 112 | adantr |  |-  ( ( ( d e. Word V /\ x e. Word V ) /\ ( d =/= (/) /\ x =/= (/) ) ) -> d e. Word V ) | 
						
							| 114 |  | simpr |  |-  ( ( d e. Word V /\ x e. Word V ) -> x e. Word V ) | 
						
							| 115 | 114 | adantr |  |-  ( ( ( d e. Word V /\ x e. Word V ) /\ ( d =/= (/) /\ x =/= (/) ) ) -> x e. Word V ) | 
						
							| 116 |  | hashneq0 |  |-  ( d e. Word V -> ( 0 < ( # ` d ) <-> d =/= (/) ) ) | 
						
							| 117 | 116 | biimprd |  |-  ( d e. Word V -> ( d =/= (/) -> 0 < ( # ` d ) ) ) | 
						
							| 118 | 117 | adantr |  |-  ( ( d e. Word V /\ x e. Word V ) -> ( d =/= (/) -> 0 < ( # ` d ) ) ) | 
						
							| 119 | 118 | com12 |  |-  ( d =/= (/) -> ( ( d e. Word V /\ x e. Word V ) -> 0 < ( # ` d ) ) ) | 
						
							| 120 | 119 | adantr |  |-  ( ( d =/= (/) /\ x =/= (/) ) -> ( ( d e. Word V /\ x e. Word V ) -> 0 < ( # ` d ) ) ) | 
						
							| 121 | 120 | impcom |  |-  ( ( ( d e. Word V /\ x e. Word V ) /\ ( d =/= (/) /\ x =/= (/) ) ) -> 0 < ( # ` d ) ) | 
						
							| 122 |  | pfxsuff1eqwrdeq |  |-  ( ( d e. Word V /\ x e. Word V /\ 0 < ( # ` d ) ) -> ( d = x <-> ( ( # ` d ) = ( # ` x ) /\ ( ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) /\ ( lastS ` d ) = ( lastS ` x ) ) ) ) ) | 
						
							| 123 | 113 115 121 122 | syl3anc |  |-  ( ( ( d e. Word V /\ x e. Word V ) /\ ( d =/= (/) /\ x =/= (/) ) ) -> ( d = x <-> ( ( # ` d ) = ( # ` x ) /\ ( ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) /\ ( lastS ` d ) = ( lastS ` x ) ) ) ) ) | 
						
							| 124 |  | ancom |  |-  ( ( ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) /\ ( lastS ` d ) = ( lastS ` x ) ) <-> ( ( lastS ` d ) = ( lastS ` x ) /\ ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) | 
						
							| 125 | 124 | anbi2i |  |-  ( ( ( # ` d ) = ( # ` x ) /\ ( ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) /\ ( lastS ` d ) = ( lastS ` x ) ) ) <-> ( ( # ` d ) = ( # ` x ) /\ ( ( lastS ` d ) = ( lastS ` x ) /\ ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) ) | 
						
							| 126 |  | 3anass |  |-  ( ( ( # ` d ) = ( # ` x ) /\ ( lastS ` d ) = ( lastS ` x ) /\ ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) <-> ( ( # ` d ) = ( # ` x ) /\ ( ( lastS ` d ) = ( lastS ` x ) /\ ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) ) | 
						
							| 127 | 125 126 | bitr4i |  |-  ( ( ( # ` d ) = ( # ` x ) /\ ( ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) /\ ( lastS ` d ) = ( lastS ` x ) ) ) <-> ( ( # ` d ) = ( # ` x ) /\ ( lastS ` d ) = ( lastS ` x ) /\ ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) | 
						
							| 128 | 123 127 | bitrdi |  |-  ( ( ( d e. Word V /\ x e. Word V ) /\ ( d =/= (/) /\ x =/= (/) ) ) -> ( d = x <-> ( ( # ` d ) = ( # ` x ) /\ ( lastS ` d ) = ( lastS ` x ) /\ ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) ) | 
						
							| 129 | 111 128 | syl |  |-  ( ( ( ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) /\ ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) ) /\ N e. NN0 ) /\ ( lastS ` d ) = ( lastS ` x ) ) -> ( d = x <-> ( ( # ` d ) = ( # ` x ) /\ ( lastS ` d ) = ( lastS ` x ) /\ ( d prefix ( ( # ` d ) - 1 ) ) = ( x prefix ( ( # ` d ) - 1 ) ) ) ) ) | 
						
							| 130 | 40 41 74 129 | mpbir3and |  |-  ( ( ( ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) /\ ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) ) /\ N e. NN0 ) /\ ( lastS ` d ) = ( lastS ` x ) ) -> d = x ) | 
						
							| 131 | 130 | exp31 |  |-  ( ( ( d e. Word V /\ ( ( # ` d ) = ( N + 2 ) /\ ( d prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` d ) } e. E ) ) /\ ( x e. Word V /\ ( ( # ` x ) = ( N + 2 ) /\ ( x prefix ( N + 1 ) ) = W /\ { ( lastS ` W ) , ( lastS ` x ) } e. E ) ) ) -> ( N e. NN0 -> ( ( lastS ` d ) = ( lastS ` x ) -> d = x ) ) ) | 
						
							| 132 | 22 30 131 | syl2anb |  |-  ( ( d e. D /\ x e. D ) -> ( N e. NN0 -> ( ( lastS ` d ) = ( lastS ` x ) -> d = x ) ) ) | 
						
							| 133 | 132 | impcom |  |-  ( ( N e. NN0 /\ ( d e. D /\ x e. D ) ) -> ( ( lastS ` d ) = ( lastS ` x ) -> d = x ) ) | 
						
							| 134 | 14 133 | sylbid |  |-  ( ( N e. NN0 /\ ( d e. D /\ x e. D ) ) -> ( ( F ` d ) = ( F ` x ) -> d = x ) ) | 
						
							| 135 | 134 | ralrimivva |  |-  ( N e. NN0 -> A. d e. D A. x e. D ( ( F ` d ) = ( F ` x ) -> d = x ) ) | 
						
							| 136 |  | dff13 |  |-  ( F : D -1-1-> R <-> ( F : D --> R /\ A. d e. D A. x e. D ( ( F ` d ) = ( F ` x ) -> d = x ) ) ) | 
						
							| 137 | 6 135 136 | sylanbrc |  |-  ( N e. NN0 -> F : D -1-1-> R ) |