let X be non empty finite set ; for B being Subset-Family of holds B c= saturated-subsets (X deps_encl_by B)
let B be Subset-Family of ; B c= saturated-subsets (X deps_encl_by B)
set F = X deps_encl_by B;
reconsider F' = X deps_encl_by B as Full-family of X by Th35;
set ss = saturated-subsets (X deps_encl_by B);
set M = Maximal_wrt F';
let x be set ; TARSKI:def 3 ( not x in B or x in saturated-subsets (X deps_encl_by B) )
assume A1:
x in B
; x in saturated-subsets (X deps_encl_by B)
then reconsider x' = x as Element of B ;
reconsider x'' = x as Subset of by A1;
Maximal_wrt F' is (M1)
by Th30;
then consider a', b' being Subset of such that
A2:
[a',b'] >= [x'',x'']
and
A3:
[a',b'] in Maximal_wrt F'
by Def19;
A4:
a' c= x''
by A2, Th15;
[a',b'] in X deps_encl_by B
by A3;
then consider a, b being Subset of such that
A5:
[a',b'] = [a,b]
and
A6:
for c being set st c in B & a c= c holds
b c= c
;
A7:
a ^|^ b,X deps_encl_by B
by A3, A5, Def18;
a' = a
by A5, ZFMISC_1:33;
then A8:
b c= x'
by A1, A4, A6;
A9:
b' = b
by A5, ZFMISC_1:33;
x'' c= b'
by A2, Th15;
then
b = x
by A9, A8, XBOOLE_0:def 10;
hence
x in saturated-subsets (X deps_encl_by B)
by A7; verum