Metamath Proof Explorer


Theorem wlkpvtx

Description: A walk connects vertices. (Contributed by AV, 22-Feb-2021)

Ref Expression
Hypothesis wlkpvtx.v
|- V = ( Vtx ` G )
Assertion wlkpvtx
|- ( F ( Walks ` G ) P -> ( N e. ( 0 ... ( # ` F ) ) -> ( P ` N ) e. V ) )

Proof

Step Hyp Ref Expression
1 wlkpvtx.v
 |-  V = ( Vtx ` G )
2 1 wlkp
 |-  ( F ( Walks ` G ) P -> P : ( 0 ... ( # ` F ) ) --> V )
3 ffvelrn
 |-  ( ( P : ( 0 ... ( # ` F ) ) --> V /\ N e. ( 0 ... ( # ` F ) ) ) -> ( P ` N ) e. V )
4 3 ex
 |-  ( P : ( 0 ... ( # ` F ) ) --> V -> ( N e. ( 0 ... ( # ` F ) ) -> ( P ` N ) e. V ) )
5 2 4 syl
 |-  ( F ( Walks ` G ) P -> ( N e. ( 0 ... ( # ` F ) ) -> ( P ` N ) e. V ) )