Metamath Proof Explorer


Theorem 3exbidv

Description: Formula-building rule for three existential quantifiers (deduction form). (Contributed by NM, 1-May-1995)

Ref Expression
Hypothesis 3exbidv.1 φψχ
Assertion 3exbidv φxyzψxyzχ

Proof

Step Hyp Ref Expression
1 3exbidv.1 φψχ
2 1 exbidv φzψzχ
3 2 2exbidv φxyzψxyzχ