Set comparison

bool contains(const std::complex<T>& v) const; 
bool contains(const kc_interval<T>& o) const; 
bool overlaps(const kc_interval<T>& o) const;

contains(const std::complex<T>& v): Determines whether the given $v ∈C$ is in the current interval $X ∈ KC$ , that is $v∈ X$ .
contains(const kc_interval<T>& o): Determines whether the given $O ∈ KC$ is contained in the current interval $X ∈KC$ , that is $O ∈ X$ .
overlaps(const kc_interval<T>& o): Determines whether the given $O ∈KC$ overlaps with the current interval $X∈ KC$ , that is $∃v∈R$ such that $v∈ O∧ v∈ X$ .