Metamath Proof Explorer


Theorem 0in

Description: The intersection of the empty set with a class is the empty set. (Contributed by Glauco Siliprandi, 17-Aug-2020)

Ref Expression
Assertion 0in A=

Proof

Step Hyp Ref Expression
1 incom A=A
2 in0 A=
3 1 2 eqtri A=