Metamath Proof Explorer
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 |
⊢ ( 𝐺 ∈ 𝑉 → ( .ef ‘ 𝐺 ) = ( 𝐺 ‘ ( .ef ‘ ndx ) ) ) |
Proof
Step |
Hyp |
Ref |
Expression |
1 |
|
id |
⊢ ( 𝐺 ∈ 𝑉 → 𝐺 ∈ 𝑉 ) |
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 |
⊢ ( 𝐺 ∈ 𝑉 → ( 𝐺 ‘ ( .ef ‘ ndx ) ) = ( .ef ‘ 𝐺 ) ) |
7 |
6
|
eqcomd |
⊢ ( 𝐺 ∈ 𝑉 → ( .ef ‘ 𝐺 ) = ( 𝐺 ‘ ( .ef ‘ ndx ) ) ) |