Theorem 3orcoma 942

Description: Commutation law for triple disjunction. (Contributed by Mario Carneiro, 4-Sep-2016.)

Assertion

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

Proof of Theorem 3orcoma

Step	Hyp	Ref	Expression
1		or12 509	. 2 |- ((ph \/ (ps \/ ch)) <-> (ps \/ (ph \/ ch)))
2		3orass 937	. 2 |- ((ph \/ ps \/ ch) <-> (ph \/ (ps \/ ch)))
3		3orass 937	. 2 |- ((ps \/ ph \/ ch) <-> (ps \/ (ph \/ ch)))
4	1, 2, 3	3bitr4i 268	1 |- ((ph \/ ps \/ ch) <-> (ps \/ ph \/ ch))

Syntax hints:   <-> wb 176   \/ wo 357   \/ w3o 933

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This theorem depends on definitions:  df-bi 177  df-or 359  df-3or 935

This theorem is referenced by:  cadcomb  1396