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 xAyBzCφ
Assertion rspec3 xAyBzCφ

Proof

Step Hyp Ref Expression
1 rspec3.1 xAyBzCφ
2 1 rspec2 xAyBzCφ
3 2 r19.21bi xAyBzCφ
4 3 3impa xAyBzCφ