Status functions

bool is_empty() const; 
bool is_whole() const; 
bool is_singleton() const; 
bool is_okay() const;

These functions return the status of the current interval $k∈ KC$ :

is_empty(): Whether the interval is empty $k =∅$ .
is_whole(): Whether the interval spans the whole complex space $k̸= ∅∧ kr= ∞$ .
is_whole(): Whether the interval refers to a single complex number. $k ̸=∅ ∧kr =0$ .
is_okay(): Whether the interval is properly defined, i.e. whether $kr≥ 0$ .