Theorem simplimdc 850

Description: Simplification for a decidable proposition. Similar to Theorem *3.26 (Simp) of [WhiteheadRussell] p. 112. (Contributed by Jim Kingdon, 29-Mar-2018.)

Assertion

Ref	Expression
simplimdc	|- (DECID ph -> ( -. ( ph -> ps ) -> ph ) )

Proof of Theorem simplimdc

Step	Hyp	Ref	Expression
1		pm2.21 607	. 2 |- ( -. ph -> ( ph -> ps ) )
2		con1dc 846	. 2 |- (DECID ph -> ( ( -. ph -> ( ph -> ps ) ) -> ( -. ( ph -> ps ) -> ph ) ) )
3	1, 2	mpi 15	1 |- (DECID ph -> ( -. ( ph -> ps ) -> ph ) )

Syntax hints:   -. wn 3   -> wi 4  DECID wdc 824

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 604  ax-in2 605  ax-io 699

This theorem depends on definitions:  df-bi 116  df-stab 821  df-dc 825

This theorem is referenced by:  pm2.5gdc  856  dfandc  874  pm4.79dc  893