Metamath Proof Explorer


Theorem tsksn

Description: A singleton of an element of a Tarski class belongs to the class. JFM CLASSES2 th. 2 (partly). (Contributed by FL, 22-Feb-2011) (Revised by Mario Carneiro, 18-Jun-2013)

Ref Expression
Assertion tsksn TTarskiATAT

Proof

Step Hyp Ref Expression
1 tskpw TTarskiAT𝒫AT
2 snsspw A𝒫A
3 tskss TTarski𝒫ATA𝒫AAT
4 2 3 mp3an3 TTarski𝒫ATAT
5 1 4 syldan TTarskiATAT