theorem Th45: :: YELLOW12:45

for S being non empty TopSpace
for T being non empty Hausdorff TopSpace
for f, g being continuous Function of S,T holds
( ( for X being Subset of S st X = { p where p is Point of S : f . p <> g . p } holds
X is open ) & ( for X being Subset of S st X = { p where p is Point of S : f . p = g . p } holds
X is closed ) )