Theorem 19.33bdc 1644

Description: Converse of 19.33 1498 given -. ( E. x ph /\ E. x ps ) and a decidability condition. Compare Theorem 19.33 of [Margaris] p. 90. For a version which does not require a decidability condition, see 19.33b2 1643 (Contributed by Jim Kingdon, 23-Apr-2018.)

Assertion

Ref	Expression
19.33bdc	|- (DECID E. x ph -> ( -. ( E. x ph /\ E. x ps ) -> ( A. x ( ph \/ ps ) <-> ( A. x ph \/ A. x ps ) ) ) )

Proof of Theorem 19.33bdc

Step	Hyp	Ref	Expression
1		ianordc 900	. 2 |- (DECID E. x ph -> ( -. ( E. x ph /\ E. x ps ) <-> ( -. E. x ph \/ -. E. x ps ) ) )
2		19.33b2 1643	. 2 |- ( ( -. E. x ph \/ -. E. x ps ) -> ( A. x ( ph \/ ps ) <-> ( A. x ph \/ A. x ps ) ) )
3	1, 2	biimtrdi 163	1 |- (DECID E. x ph -> ( -. ( E. x ph /\ E. x ps ) -> ( A. x ( ph \/ ps ) <-> ( A. x ph \/ A. x ps ) ) ) )

Syntax hints:   -. wn 3   -> wi 4   /\ wa 104   <-> wb 105   \/ wo 709  DECID wdc 835   A.wal 1362   E.wex 1506

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-in1 615  ax-in2 616  ax-io 710  ax-5 1461  ax-gen 1463  ax-ie2 1508

This theorem depends on definitions:  df-bi 117  df-dc 836  df-tru 1367  df-fal 1370

This theorem is referenced by: (None)