theorem Th45: :: CARD_3:45

for X being set st X is c=-linear holds
ex Y being set st
( Y c= X & union Y = union X & ( for Z being set st Z c= Y & Z <> {} holds
ex Z1 being set st
( Z1 in Z & ( for Z2 being set st Z2 in Z holds
Z1 c= Z2 ) ) ) )