Theorem pm3.27im 140

Description: Simplification. Similar to Theorem *3.27 (Simp) of [WhiteheadRussell] p. 112.

Assertion

Ref	Expression
pm3.27im	|- (-. (ph -> -. ps) -> ps)

Proof of Theorem pm3.27im

Step	Hyp	Ref	Expression
1		ax-1 4	. 2 |- (-. ps -> (ph -> -. ps))
2	1	con1i 96	1 |- (-. (ph -> -. ps) -> ps)

Syntax hints:  -. wn 2   -> wi 3

This theorem is referenced by:  bi2 149  bi3 150  pm3.27 323

This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7

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