theorem Th14: :: PARTIT_2:14

for Y being non empty set
for G being Subset of (PARTITIONS Y) st G is independent holds
for P, Q being Subset of (PARTITIONS Y) st P c= G & Q c= G holds
(ERl ('/\' P)) * (ERl ('/\' Q)) = (ERl ('/\' Q)) * (ERl ('/\' P)) by Lm1;