for T being non empty normal TopSpace
for A, B being closed Subset of T st A <> {} & A misses B holds
for G being Rain of A,B ex F being Function of DOM,(bool the carrier of T) st
for x being Real st x in DOM holds
( ( x in halfline 0 implies F . x = {} ) & ( x in right_open_halfline 1 implies F . x = the carrier of T ) & ( x in DYADIC implies for n being Nat st x in dyadic n holds
F . x = (G . n) . x ) )