Metamath Proof Explorer


Theorem iedginwlk

Description: The value of the edge function for an index of an edge within a walk is an edge. (Contributed by AV, 23-Apr-2021)

Ref Expression
Hypothesis iedginwlk.i ⊢ I = iEdg ⁡ G
Assertion iedginwlk ⊢ Fun ⁡ I ∧ F Walks ⁡ G P ∧ X ∈ 0 ..^ F → I ⁡ F ⁡ X ∈ ran ⁡ I

Proof

Step Hyp Ref Expression
1 iedginwlk.i ⊢ I = iEdg ⁡ G
2 simp1 ⊢ Fun ⁡ I ∧ F Walks ⁡ G P ∧ X ∈ 0 ..^ F → Fun ⁡ I
3 1 wlkf ⊢ F Walks ⁡ G P → F ∈ Word dom ⁡ I
4 3 3ad2ant2 ⊢ Fun ⁡ I ∧ F Walks ⁡ G P ∧ X ∈ 0 ..^ F → F ∈ Word dom ⁡ I
5 simp3 ⊢ Fun ⁡ I ∧ F Walks ⁡ G P ∧ X ∈ 0 ..^ F → X ∈ 0 ..^ F
6 wrdsymbcl ⊢ F ∈ Word dom ⁡ I ∧ X ∈ 0 ..^ F → F ⁡ X ∈ dom ⁡ I
7 4 5 6 syl2anc ⊢ Fun ⁡ I ∧ F Walks ⁡ G P ∧ X ∈ 0 ..^ F → F ⁡ X ∈ dom ⁡ I
8 fvelrn ⊢ Fun ⁡ I ∧ F ⁡ X ∈ dom ⁡ I → I ⁡ F ⁡ X ∈ ran ⁡ I
9 2 7 8 syl2anc ⊢ Fun ⁡ I ∧ F Walks ⁡ G P ∧ X ∈ 0 ..^ F → I ⁡ F ⁡ X ∈ ran ⁡ I