theorem Th21: :: METRIZTS:21

for TM being metrizable TopSpace
for iC being infinite Cardinal holds
( weight TM c= iC iff for Fm being Subset-Family of TM st Fm is open & not {} in Fm & ( for Am, Bm being Subset of TM st Am in Fm & Bm in Fm & Am <> Bm holds
Am misses Bm ) holds
card Fm c= iC )