2.1.101 Constructing the prolog head and the send_method

The head is used to construct a send_method object. The selector of this send method is the functor of the head. The type specification is used to create the type-check vector for the send_method. The implementing method is a message to @prolog. The selector (which equals the predicate name) is

`send_Selector_Class`

and the arguments are @receiver, @arg1, @arg2, ... (just as many arguments as the method has).