Primitive constraints

A primitive constraint is a call in the form,

		  E1 R E2

where E1 and E2 are two linear arithmetic expressions and R is an arithmetic relation symbol. An arithmetic expression is made of integers, variables, domain variables, and the following four arithmetic functions: +, -, * and /.

• ?E1 #= ?E2 E1 and E2 are equal.

• ?E1 #\= ?E2 E1 and E2 are different.

• ?E1 #> ?E2 E1 is greater than E2.

• ?E1 #>= ?E2 E1 is greater than or equal to E2.

• ?E1 #< ?E2 E1 is less than E2.

• ?E1 #=< ?E2 E1 is less than or equal to E2.