let X be non empty TopSpace; for X1, X2 being non empty SubSpace of X st X1,X2 constitute_a_decomposition holds
( X1,X2 are_weakly_separated iff X1,X2 are_separated )
let X1, X2 be non empty SubSpace of X; ( X1,X2 constitute_a_decomposition implies ( X1,X2 are_weakly_separated iff X1,X2 are_separated ) )
assume
X1,X2 constitute_a_decomposition
; ( X1,X2 are_weakly_separated iff X1,X2 are_separated )
then
X1 misses X2
by Th30;
hence
( X1,X2 are_weakly_separated iff X1,X2 are_separated )
by TSEP_1:78; verum