As an example, consider a binary functor $$f_{0} and two binary functors $$f_{1} and $$f_{2}. Composing $$f_{1} and $$f_{2} into $$f_{0} yields a new binary functor
$$ f: (x_{0},x_{1}) f_{0}(f_{1}(x_{0},x_{1}),f_{2}(x_{0},x_{1})).
#include <CGAL/functional.h>
 
 
 
returns the functor
f0(f1($$ · ),$$f2($$ · )) with the same
arity as $$f1 (and $$f2).
 
 
 
 
returns the functor
f0(f1($$ · ),$$f2($$ · ),$$f3($$ · ))
with the same arity as $$f1 (and $$f2, $$f3).
