Metamath Proof Explorer


Theorem wl-rgenw

Description: Generalization rule for restricted quantification. (Contributed by Wolf Lammen, 10-Jun-2023)

Ref Expression
Hypothesis wl-rgenw.1 φ
Assertion wl-rgenw x : A φ

Proof

Step Hyp Ref Expression
1 wl-rgenw.1 φ
2 wl-dfralsb x : A φ z z A z x φ
3 1 sbt z x φ
4 3 a1i z A z x φ
5 2 4 mpgbir x : A φ