Relation _SELF-CONNECTED

(self-)connectedness in an object (even a space)
arises when it is the sum of two parts whose interiors have connected complements.
Arity: 2
Subrelation-Of: Topological-property
Axioms:
(=> (_Self-Connected ?A ?B)
    (Exists (?Y ?Z)
            (And (Object ?Y)
                 (Object ?Z)
                 (Exists (?C)
                         (And (Mereo-Sum ?Y ?Z ?C) (Identity ?A ?C)))
                 (Exists (?D ?E ?F ?G)
                         (And (Interior ?Z ?G)
                              (T-Complement ?G ?F)
                              (Interior ?Y ?E)
                              (T-Complement ?E ?D)
                              (Connected ?D ?F))))))