Metamath Proof Explorer


Theorem encv

Description: If two classes are equinumerous, both classes are sets. (Contributed by AV, 21-Mar-2019)

Ref Expression
Assertion encv ( 𝐴𝐵 → ( 𝐴 ∈ V ∧ 𝐵 ∈ V ) )

Proof

Step Hyp Ref Expression
1 relen Rel ≈
2 1 brrelex12i ( 𝐴𝐵 → ( 𝐴 ∈ V ∧ 𝐵 ∈ V ) )