Metamath Proof Explorer


Theorem edgfndxid

Description: The value of the edge function extractor is the value of the corresponding slot of the structure. (Contributed by AV, 21-Sep-2020)

Ref Expression
Assertion edgfndxid ( 𝐺𝑉 → ( .ef ‘ 𝐺 ) = ( 𝐺 ‘ ( .ef ‘ ndx ) ) )

Proof

Step Hyp Ref Expression
1 id ( 𝐺𝑉𝐺𝑉 )
2 df-edgf .ef = Slot 1 8
3 1nn0 1 ∈ ℕ0
4 8nn 8 ∈ ℕ
5 3 4 decnncl 1 8 ∈ ℕ
6 1 2 5 strndxid ( 𝐺𝑉 → ( 𝐺 ‘ ( .ef ‘ ndx ) ) = ( .ef ‘ 𝐺 ) )
7 6 eqcomd ( 𝐺𝑉 → ( .ef ‘ 𝐺 ) = ( 𝐺 ‘ ( .ef ‘ ndx ) ) )