Theorem 3jaob 1233

Description: Disjunction of 3 antecedents. (Contributed by NM, 13-Sep-2011.)

Assertion

Ref	Expression
3jaob	|- ( ( ( ph \/ ch \/ th ) -> ps ) <-> ( ( ph -> ps ) /\ ( ch -> ps ) /\ ( th -> ps ) ) )

Proof of Theorem 3jaob

Step	Hyp	Ref	Expression
1		3mix1 1107	. . . 4 |- ( ph -> ( ph \/ ch \/ th ) )
2	1	imim1i 59	. . 3 |- ( ( ( ph \/ ch \/ th ) -> ps ) -> ( ph -> ps ) )
3		3mix2 1108	. . . 4 |- ( ch -> ( ph \/ ch \/ th ) )
4	3	imim1i 59	. . 3 |- ( ( ( ph \/ ch \/ th ) -> ps ) -> ( ch -> ps ) )
5		3mix3 1109	. . . 4 |- ( th -> ( ph \/ ch \/ th ) )
6	5	imim1i 59	. . 3 |- ( ( ( ph \/ ch \/ th ) -> ps ) -> ( th -> ps ) )
7	2, 4, 6	3jca 1118	. 2 |- ( ( ( ph \/ ch \/ th ) -> ps ) -> ( ( ph -> ps ) /\ ( ch -> ps ) /\ ( th -> ps ) ) )
8		3jao 1232	. 2 |- ( ( ( ph -> ps ) /\ ( ch -> ps ) /\ ( th -> ps ) ) -> ( ( ph \/ ch \/ th ) -> ps ) )
9	7, 8	impbii 124	1 |- ( ( ( ph \/ ch \/ th ) -> ps ) <-> ( ( ph -> ps ) /\ ( ch -> ps ) /\ ( th -> ps ) ) )

Syntax hints:   -> wi 4   <-> wb 103   \/ w3o 918   /\ w3a 919

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-io 662

This theorem depends on definitions:  df-bi 115  df-3or 920  df-3an 921

This theorem is referenced by: (None)