operand type(s) and result type.

<pre>
     Op1      Op2      Result     Operation

=    integer   integer   Boolean     integer equality
     Boolean   Boolean   Boolean     Boolean equality
#    integer   integer   Boolean     integer inequality
     Boolean   Boolean   Boolean     Boolean inequality
&lt;    integer   integer   Boolean     integer less than
&gt;    integer   integer   Boolean     integer greater than
+    integer   integer   integer     integer addition
-    integer   integer   integer  