Compound Terms

A Compound Term is a functor with a (fixed) number of arguments each of which may be a Prolog term.

This means that we can arbitrarily nest compound terms. For some examples:

 
happy(fred)

				principal functor		 = 		 happy

				1st argument	 		 = 		 a constant (atom)

sum(5,X)

				principal functor		 = 		 sum

				1st argument	 		 = 		 constant (integer)

				2nd argument     		 = 		 variable

not(happy(woman))

				principal functor		 = 		 not

				1st argument     		 = 		 compound term

Nesting compound terms may be of use to the programmer. For example, the clause

 
fact(fred,10000).

 
fact(name(fred),salary(10000)).