theorem Th14: :: BVFUNC11:14
for Y being non empty set
for a being Function of Y,BOOLEAN
for G being Subset of (PARTITIONS Y)
for A, B being a_partition of Y st G is independent holds
Ex (('not' (All (a,A,G))),B,G) '<' Ex ((Ex (('not' a),B,G)),A,G)