Metamath Proof Explorer


Theorem unisn0

Description: The union of the singleton of the empty set is the empty set. (Contributed by Glauco Siliprandi, 17-Aug-2020)

Ref Expression
Assertion unisn0 =

Proof

Step Hyp Ref Expression
1 ssid
2 uni0b =
3 1 2 mpbir =