Metamath Proof Explorer


Theorem omiscard

Description: _om is a cardinal number. (Contributed by RP, 1-Oct-2023)

Ref Expression
Assertion omiscard ωrancard

Proof

Step Hyp Ref Expression
1 omelon ωOn
2 nnsdom xωxω
3 sdomnen xω¬xω
4 2 3 syl xω¬xω
5 4 rgen xω¬xω
6 elrncard ωrancardωOnxω¬xω
7 1 5 6 mpbir2an ωrancard