Metamath Proof Explorer


Theorem upgrimpthslem1

Description: Lemma 1 for upgrimpths . (Contributed by AV, 30-Oct-2025)

Ref Expression
Hypotheses upgrimwlk.i I = iEdg G
upgrimwlk.j J = iEdg H
upgrimwlk.g φ G USHGraph
upgrimwlk.h φ H USHGraph
upgrimwlk.n φ N G GraphIso H
upgrimwlk.e E = x dom F J -1 N I F x
upgrimpths.p φ F Paths G P
Assertion upgrimpthslem1 φ Fun N P 1 ..^ F -1

Proof

Step Hyp Ref Expression
1 upgrimwlk.i I = iEdg G
2 upgrimwlk.j J = iEdg H
3 upgrimwlk.g φ G USHGraph
4 upgrimwlk.h φ H USHGraph
5 upgrimwlk.n φ N G GraphIso H
6 upgrimwlk.e E = x dom F J -1 N I F x
7 upgrimpths.p φ F Paths G P
8 ispth F Paths G P F Trails G P Fun P 1 ..^ F -1 P 0 F P 1 ..^ F =
9 8 simp2bi F Paths G P Fun P 1 ..^ F -1
10 7 9 syl φ Fun P 1 ..^ F -1
11 eqid Vtx G = Vtx G
12 eqid Vtx H = Vtx H
13 11 12 grimf1o N G GraphIso H N : Vtx G 1-1 onto Vtx H
14 dff1o3 N : Vtx G 1-1 onto Vtx H N : Vtx G onto Vtx H Fun N -1
15 14 simprbi N : Vtx G 1-1 onto Vtx H Fun N -1
16 5 13 15 3syl φ Fun N -1
17 funco Fun P 1 ..^ F -1 Fun N -1 Fun P 1 ..^ F -1 N -1
18 10 16 17 syl2anc φ Fun P 1 ..^ F -1 N -1
19 resco N P 1 ..^ F = N P 1 ..^ F
20 19 cnveqi N P 1 ..^ F -1 = N P 1 ..^ F -1
21 cnvco N P 1 ..^ F -1 = P 1 ..^ F -1 N -1
22 20 21 eqtri N P 1 ..^ F -1 = P 1 ..^ F -1 N -1
23 22 funeqi Fun N P 1 ..^ F -1 Fun P 1 ..^ F -1 N -1
24 18 23 sylibr φ Fun N P 1 ..^ F -1