let X be non empty TopSpace; for A1, A2 being Subset of X st A1,A2 constitute_a_decomposition holds
( A1,A2 are_weakly_separated iff A1,A2 are_separated )
let A1, A2 be Subset of X; ( A1,A2 constitute_a_decomposition implies ( A1,A2 are_weakly_separated iff A1,A2 are_separated ) )
assume
A1,A2 constitute_a_decomposition
; ( A1,A2 are_weakly_separated iff A1,A2 are_separated )
then
A1 misses A2
by Def1;
hence
( A1,A2 are_weakly_separated iff A1,A2 are_separated )
by TSEP_1:46; verum