Metamath Proof Explorer


Theorem isomuspgrlem2a

Description: Lemma 1 for isomuspgrlem2 . (Contributed by AV, 29-Nov-2022)

Ref Expression
Hypotheses isomushgr.v
|- V = ( Vtx ` A )
isomushgr.w
|- W = ( Vtx ` B )
isomushgr.e
|- E = ( Edg ` A )
isomushgr.k
|- K = ( Edg ` B )
isomuspgrlem2.g
|- G = ( x e. E |-> ( F " x ) )
Assertion isomuspgrlem2a
|- ( F e. X -> A. e e. E ( F " e ) = ( G ` e ) )

Proof

Step Hyp Ref Expression
1 isomushgr.v
 |-  V = ( Vtx ` A )
2 isomushgr.w
 |-  W = ( Vtx ` B )
3 isomushgr.e
 |-  E = ( Edg ` A )
4 isomushgr.k
 |-  K = ( Edg ` B )
5 isomuspgrlem2.g
 |-  G = ( x e. E |-> ( F " x ) )
6 5 a1i
 |-  ( ( F e. X /\ e e. E ) -> G = ( x e. E |-> ( F " x ) ) )
7 imaeq2
 |-  ( x = e -> ( F " x ) = ( F " e ) )
8 7 adantl
 |-  ( ( ( F e. X /\ e e. E ) /\ x = e ) -> ( F " x ) = ( F " e ) )
9 simpr
 |-  ( ( F e. X /\ e e. E ) -> e e. E )
10 imaexg
 |-  ( F e. X -> ( F " e ) e. _V )
11 10 adantr
 |-  ( ( F e. X /\ e e. E ) -> ( F " e ) e. _V )
12 6 8 9 11 fvmptd
 |-  ( ( F e. X /\ e e. E ) -> ( G ` e ) = ( F " e ) )
13 12 eqcomd
 |-  ( ( F e. X /\ e e. E ) -> ( F " e ) = ( G ` e ) )
14 13 ralrimiva
 |-  ( F e. X -> A. e e. E ( F " e ) = ( G ` e ) )