let M be non limit_cardinal Aleph; :: thesis: for F being Filter of M holds
( not F is uniform or not F is being_ultrafilter or not F is_complete_with M )
given F being Filter of M such that A1:
( F is uniform & F is being_ultrafilter & F is_complete_with M )
; :: thesis: contradiction
Frechet_Ideal M c= dual F
then consider S being Subset-Family of M such that
A5:
card S = M
and
A6:
for X1 being set st X1 in S holds
not X1 in dual F
and
A7:
for X1, X2 being set st X1 in S & X2 in S & X1 <> X2 holds
X1 misses X2
by A1, Th12, Th35;
A8:
for X1 being set st X1 in S holds
X1 in F
not S is finite
by A5;
then consider X1 being set such that
A11:
X1 in S
by XBOOLE_0:def 1;
S \ {X1} <> {}
then consider X2 being set such that
A12:
X2 in S \ {X1}
by XBOOLE_0:def 1;
A13:
S \ {X1} is Subset of S
;
not X2 in {X1}
by A12, XBOOLE_0:def 5;
then
( X2 in S & X2 <> X1 )
by A12, A13, TARSKI:def 1;
then
X1 misses X2
by A7, A11;
then A14:
X1 /\ X2 = {}
by XBOOLE_0:def 7;
reconsider X1 = X1, X2 = X2 as Subset of M by A11, A12;
( X1 in F & X2 in F )
by A8, A11, A12, A13;
then
{} in F
by A14, Def1;
hence
contradiction
by Def1; :: thesis: verum