Metamath Proof Explorer


Theorem numufl

Description: Consequence of filssufilg : a set whose double powerset is well-orderable satisfies the ultrafilter lemma. (Contributed by Mario Carneiro, 26-Aug-2015)

Ref Expression
Assertion numufl
|- ( ~P ~P X e. dom card -> X e. UFL )

Proof

Step Hyp Ref Expression
1 filssufilg
 |-  ( ( f e. ( Fil ` X ) /\ ~P ~P X e. dom card ) -> E. g e. ( UFil ` X ) f C_ g )
2 1 ancoms
 |-  ( ( ~P ~P X e. dom card /\ f e. ( Fil ` X ) ) -> E. g e. ( UFil ` X ) f C_ g )
3 2 ralrimiva
 |-  ( ~P ~P X e. dom card -> A. f e. ( Fil ` X ) E. g e. ( UFil ` X ) f C_ g )
4 pwexr
 |-  ( ~P ~P X e. dom card -> ~P X e. _V )
5 pwexb
 |-  ( X e. _V <-> ~P X e. _V )
6 4 5 sylibr
 |-  ( ~P ~P X e. dom card -> X e. _V )
7 isufl
 |-  ( X e. _V -> ( X e. UFL <-> A. f e. ( Fil ` X ) E. g e. ( UFil ` X ) f C_ g ) )
8 6 7 syl
 |-  ( ~P ~P X e. dom card -> ( X e. UFL <-> A. f e. ( Fil ` X ) E. g e. ( UFil ` X ) f C_ g ) )
9 3 8 mpbird
 |-  ( ~P ~P X e. dom card -> X e. UFL )