Metamath Proof Explorer


Theorem mpgbi

Description: Modus ponens on biconditional combined with generalization. (Contributed by NM, 24-May-1994) (Proof shortened by Stefan Allan, 28-Oct-2008)

Ref Expression
Hypotheses mpgbi.1
|- ( A. x ph <-> ps )
mpgbi.2
|- ph
Assertion mpgbi
|- ps

Proof

Step Hyp Ref Expression
1 mpgbi.1
 |-  ( A. x ph <-> ps )
2 mpgbi.2
 |-  ph
3 2 ax-gen
 |-  A. x ph
4 3 1 mpbi
 |-  ps