Theorem 3anbi12d 1208

Description: Deduction conjoining and adding a conjunct to equivalences. (Contributed by NM, 8-Sep-2006.)

Hypotheses

Ref	Expression
3anbi12d.1	|- ( ph -> ( ps <-> ch ) )
3anbi12d.2	|- ( ph -> ( th <-> ta ) )

Assertion

Ref	Expression
3anbi12d	|- ( ph -> ( ( ps /\ th /\ et ) <-> ( ch /\ ta /\ et ) ) )

Proof of Theorem 3anbi12d

Step	Hyp	Ref	Expression
1		3anbi12d.1	. 2 |- ( ph -> ( ps <-> ch ) )
2		3anbi12d.2	. 2 |- ( ph -> ( th <-> ta ) )
3		biidd 161	. 2 |- ( ph -> ( et <-> et ) )
4	1, 2, 3	3anbi123d 1207	1 |- ( ph -> ( ( ps /\ th /\ et ) <-> ( ch /\ ta /\ et ) ) )

Syntax hints:   -> wi 4   <-> wb 98   /\ w3a 885

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101

This theorem depends on definitions:  df-bi 110  df-3an 887

This theorem is referenced by:  3anbi1d  1211  3anbi2d  1212  fseq1m1p1  8957