Metamath Proof Explorer


Theorem suppssdm

Description: The support of a function is a subset of the function's domain. (Contributed by AV, 30-May-2019)

Ref Expression
Assertion suppssdm ⊢ F supp Z ⊆ dom ⁡ F

Proof

Step Hyp Ref Expression
1 suppval ⊢ F ∈ V ∧ Z ∈ V → F supp Z = i ∈ dom ⁡ F | F i ≠ Z
2 ssrab2 ⊢ i ∈ dom ⁡ F | F i ≠ Z ⊆ dom ⁡ F
3 1 2 eqsstrdi ⊢ F ∈ V ∧ Z ∈ V → F supp Z ⊆ dom ⁡ F
4 supp0prc ⊢ ¬ F ∈ V ∧ Z ∈ V → F supp Z = ∅
5 0ss ⊢ ∅ ⊆ dom ⁡ F
6 4 5 eqsstrdi ⊢ ¬ F ∈ V ∧ Z ∈ V → F supp Z ⊆ dom ⁡ F
7 3 6 pm2.61i ⊢ F supp Z ⊆ dom ⁡ F