Theorem pm1.2 756

Description: Axiom *1.2 (Taut) of [WhiteheadRussell] p. 96. (Contributed by NM, 3-Jan-2005.) (Revised by NM, 10-Mar-2013.)

Assertion

Ref	Expression
pm1.2	|- ( ( ph \/ ph ) -> ph )

Proof of Theorem pm1.2

Step	Hyp	Ref	Expression
1		id 19	. 2 |- ( ph -> ph )
2	1, 1	jaoi 716	1 |- ( ( ph \/ ph ) -> ph )

Syntax hints:   -> wi 4   \/ wo 708

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 709

This theorem depends on definitions:  df-bi 117

This theorem is referenced by:  oridm  757  sbequi  1839  swoer  6560