theorem Th28: :: BVFUNC_2:28

for Y being non empty set
for G being Subset of (PARTITIONS Y)
for a, u being Function of Y,BOOLEAN
for PA being a_partition of Y st u is_independent_of PA,G holds
All ((u 'xor' a),PA,G) '<' u 'xor' (All (a,PA,G))