Theorem bj-axemptylem 15538

Description: Lemma for bj-axempty 15539 and bj-axempty2 15540. (Contributed by BJ, 25-Oct-2020.) (Proof modification is discouraged.) Use ax-nul 4159 instead. (New usage is discouraged.)

Assertion

Ref	Expression
bj-axemptylem	|- E. x A. y ( y e. x -> F. )

Distinct variable group:   x, y

Proof of Theorem bj-axemptylem

Dummy variable z is distinct from all other variables.

Step	Hyp	Ref	Expression
1		bdfal 15479	. . 3 |- BOUNDED F.
2	1	bdsep1 15531	. 2 |- E. x A. y ( y e. x <-> ( y e. z /\ F. ) )
3		biimp 118	. . . 4 |- ( ( y e. x <-> ( y e. z /\ F. ) ) -> ( y e. x -> ( y e. z /\ F. ) ) )
4		falimd 1379	. . . 4 |- ( ( y e. z /\ F. ) -> F. )
5	3, 4	syl6 33	. . 3 |- ( ( y e. x <-> ( y e. z /\ F. ) ) -> ( y e. x -> F. ) )
6	5	alimi 1469	. 2 |- ( A. y ( y e. x <-> ( y e. z /\ F. ) ) -> A. y ( y e. x -> F. ) )
7	2, 6	eximii 1616	1 |- E. x A. y ( y e. x -> F. )

Syntax hints:   -> wi 4   /\ wa 104   <-> wb 105   A.wal 1362   F. wfal 1369   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-5 1461  ax-gen 1463  ax-ie1 1507  ax-ie2 1508  ax-4 1524  ax-ial 1548  ax-bd0 15459  ax-bdim 15460  ax-bdn 15463  ax-bdeq 15466  ax-bdsep 15530

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

This theorem is referenced by:  bj-axempty  15539  bj-axempty2  15540