Theorem elfvm 5587

Description: If a function value has a member, the function is inhabited. (Contributed by Jim Kingdon, 14-Jun-2025.)

Assertion

Ref	Expression
elfvm	|- ( A e. ( F ` B ) -> E. j j e. F )

Distinct variable group:   j, F

Allowed substitution hints:   A( j)   B( j)

Proof of Theorem elfvm

Dummy variables k x are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		eliotaeu 5243	. . . 4 |- ( A e. ( iota x B F x ) -> E! x B F x )
2		df-fv 5262	. . . 4 |- ( F ` B ) = ( iota x B F x )
3	1, 2	eleq2s 2288	. . 3 |- ( A e. ( F ` B ) -> E! x B F x )
4		euex 2072	. . 3 |- ( E! x B F x -> E. x B F x )
5		brm 4079	. . . 4 |- ( B F x -> E. k k e. F )
6	5	exlimiv 1609	. . 3 |- ( E. x B F x -> E. k k e. F )
7	3, 4, 6	3syl 17	. 2 |- ( A e. ( F ` B ) -> E. k k e. F )
8		eleq1w 2254	. . 3 |- ( k = j -> ( k e. F <-> j e. F ) )
9	8	cbvexv 1930	. 2 |- ( E. k k e. F <-> E. j j e. F )
10	7, 9	sylib 122	1 |- ( A e. ( F ` B ) -> E. j j e. F )

Syntax hints:   -> wi 4   E.wex 1503   E!weu 2042   e. wcel 2164   class class class wbr 4029   iotacio 5213   ` cfv 5254

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-io 710  ax-5 1458  ax-7 1459  ax-gen 1460  ax-ie1 1504  ax-ie2 1505  ax-8 1515  ax-10 1516  ax-11 1517  ax-i12 1518  ax-bndl 1520  ax-4 1521  ax-17 1537  ax-i9 1541  ax-ial 1545  ax-i5r 1546  ax-ext 2175

This theorem depends on definitions:  df-bi 117  df-tru 1367  df-nf 1472  df-sb 1774  df-eu 2045  df-clab 2180  df-cleq 2186  df-clel 2189  df-nfc 2325  df-rex 2478  df-v 2762  df-sn 3624  df-uni 3836  df-br 4030  df-iota 5215  df-fv 5262

This theorem is referenced by:  basm  12679