Metamath Proof Explorer


Theorem fvclex

Description: Existence of the class of values of a set. (Contributed by NM, 9-Nov-1995)

Ref Expression
Hypothesis fvclex.1 𝐹 ∈ V
Assertion fvclex { 𝑦 ∣ ∃ 𝑥 𝑦 = ( 𝐹𝑥 ) } ∈ V

Proof

Step Hyp Ref Expression
1 fvclex.1 𝐹 ∈ V
2 1 rnex ran 𝐹 ∈ V
3 snex { ∅ } ∈ V
4 2 3 unex ( ran 𝐹 ∪ { ∅ } ) ∈ V
5 fvclss { 𝑦 ∣ ∃ 𝑥 𝑦 = ( 𝐹𝑥 ) } ⊆ ( ran 𝐹 ∪ { ∅ } )
6 4 5 ssexi { 𝑦 ∣ ∃ 𝑥 𝑦 = ( 𝐹𝑥 ) } ∈ V