Theorem luklem3 663

Description: Lemma for rederiving standard propositional axioms from Lukasiewicz'.

Assertion

Ref	Expression
luklem3	|- (ph -> (((-. ph -> ps) -> ch) -> (th -> ch)))

Proof of Theorem luklem3

Step	Hyp	Ref	Expression
1		luk-3 660	. 2 |- (ph -> (-. ph -> -. th))
2		luklem2 662	. 2 |- ((-. ph -> -. th) -> (((-. ph -> ps) -> ch) -> (th -> ch)))
3	1, 2	luklem1 661	1 |- (ph -> (((-. ph -> ps) -> ch) -> (th -> ch)))

Syntax hints:  -. wn 1   -> wi 2

This theorem is referenced by:  luklem4 664  luklem5 665

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

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