A relation condition states a relation between two operands.  The
  program compares the operands to determine whether the stated
  relation is true or false.  The first operand is called the
  condition's subject.  The second operand is called its object.
  Either operand can be: (1) an identifier, (2) a literal, or (3) the
  value of an arithmetic expression.  The set of words that specifies
  the type of comparison is called the relational operator.

  Format -

                    {IS [NOT] GREATER THAN      }
                    {IS [NOT] >                 }
                    {IS [NOT] LESS THAN         }
  {identifier-1   } {IS [NOT] <                 } {identifier-2   }
  {literal-1      } {IS [NOT] EQUAL TO          } {literal-2      }
  {arith-express-1} {IS [NOT] =                 } {arith-express-2}
                    {IS GREATER THAN OR EQUAL TO}
                    {IS >=                      }
                    {IS LESS THAN OR EQUAL TO   }
                    {IS <=                      }