Metamath Proof Explorer


Theorem suppvalfng

Description: The value of the operation constructing the support of a function with a given domain. This version of suppvalfn assumes F is a set rather than its domain X , avoiding ax-rep . (Contributed by SN, 5-Aug-2024)

Ref Expression
Assertion suppvalfng ⊢ F Fn X ∧ F ∈ V ∧ Z ∈ W → F supp Z = i ∈ X | F ⁡ i ≠ Z

Proof

Step Hyp Ref Expression
1 fnfun ⊢ F Fn X → Fun ⁡ F
2 suppval1 ⊢ Fun ⁡ F ∧ F ∈ V ∧ Z ∈ W → F supp Z = i ∈ dom ⁡ F | F ⁡ i ≠ Z
3 1 2 syl3an1 ⊢ F Fn X ∧ F ∈ V ∧ Z ∈ W → F supp Z = i ∈ dom ⁡ F | F ⁡ i ≠ Z
4 fndm ⊢ F Fn X → dom ⁡ F = X
5 4 3ad2ant1 ⊢ F Fn X ∧ F ∈ V ∧ Z ∈ W → dom ⁡ F = X
6 5 rabeqdv ⊢ F Fn X ∧ F ∈ V ∧ Z ∈ W → i ∈ dom ⁡ F | F ⁡ i ≠ Z = i ∈ X | F ⁡ i ≠ Z
7 3 6 eqtrd ⊢ F Fn X ∧ F ∈ V ∧ Z ∈ W → F supp Z = i ∈ X | F ⁡ i ≠ Z