Metamath Proof Explorer


Theorem rnfvprc

Description: The range of a function value at a proper class is empty. (Contributed by AV, 20-Aug-2022)

Ref Expression
Hypothesis rnfvprc.y ⊢ Y = F ⁡ X
Assertion rnfvprc ⊢ ¬ X ∈ V → ran ⁡ Y = ∅

Proof

Step Hyp Ref Expression
1 rnfvprc.y ⊢ Y = F ⁡ X
2 fvprc ⊢ ¬ X ∈ V → F ⁡ X = ∅
3 1 2 eqtrid ⊢ ¬ X ∈ V → Y = ∅
4 3 rneqd ⊢ ¬ X ∈ V → ran ⁡ Y = ran ⁡ ∅
5 rn0 ⊢ ran ⁡ ∅ = ∅
6 4 5 eqtrdi ⊢ ¬ X ∈ V → ran ⁡ Y = ∅