Metamath Proof Explorer


Theorem rspec3

Description: Specialization rule for restricted quantification, with three quantifiers. (Contributed by NM, 20-Nov-1994)

Ref Expression
Hypothesis rspec3.1 x A y B z C φ
Assertion rspec3 x A y B z C φ

Proof

Step Hyp Ref Expression
1 rspec3.1 x A y B z C φ
2 1 rspec2 x A y B z C φ
3 2 r19.21bi x A y B z C φ
4 3 3impa x A y B z C φ