A base class for binary functions. 
 
Expression * clone() const 
It creates a new copy of this expression. 
 
BinaryFunction & operator=(const BinaryFunction &rhs)
 
ST_Intersection & operator=(const ST_Intersection &rhs)
 
Spatial intersection operator. 
 
TE_DEFINE_VISITABLE ST_Intersection(Expression *arg1, Expression *arg2)
Constructor. 
 
This is an abstract class that models a query expression. 
 
Spatial intersects operator.