Metamath Proof Explorer


Theorem resexd

Description: The restriction of a set is a set. (Contributed by Glauco Siliprandi, 23-Oct-2021)

Ref Expression
Hypothesis resexd.1 φ A V
Assertion resexd φ A B V

Proof

Step Hyp Ref Expression
1 resexd.1 φ A V
2 resexg A V A B V
3 1 2 syl φ A B V