Theorem frege26 38104

Description: Identical to idd 24. Proposition 26 of [Frege1879] p. 42. (Contributed by RP, 24-Dec-2019.) (Proof modification is discouraged.)

Assertion

Ref	Expression
frege26	|- ( ph -> ( ps -> ps ) )

Proof of Theorem frege26

Step	Hyp	Ref	Expression
1		ax-frege1 38084	. 2 |- ( ps -> ( ph -> ps ) )
2		ax-frege8 38103	. 2 |- ( ( ps -> ( ph -> ps ) ) -> ( ph -> ( ps -> ps ) ) )
3	1, 2	ax-mp 5	1 |- ( ph -> ( ps -> ps ) )

Syntax hints:   -> wi 4

This theorem was proved from axioms:  ax-mp 5  ax-frege1 38084  ax-frege8 38103

This theorem is referenced by:  frege27  38105