let U be non empty set ; for A, B being Subset of
for F being non empty ordered Subset-Family of st F = Inter A,B holds
( min F = A & max F = B )
let A, B be Subset of ; for F being non empty ordered Subset-Family of st F = Inter A,B holds
( min F = A & max F = B )
let F be non empty ordered Subset-Family of ; ( F = Inter A,B implies ( min F = A & max F = B ) )
assume a0:
F = Inter A,B
; ( min F = A & max F = B )
( A is Element of F & ( for Y being set st Y in F holds
A c= Y ) )
by KonceWInter, a0, Lemacik;
then c1:
A = min F
by DefMi;
( B is Element of F & ( for Y being set st Y in F holds
Y c= B ) )
by KonceWInter, a0, Lemacik;
hence
( min F = A & max F = B )
by c1, DefMa; verum