Part 11
Parameter Mode "evaluates x"

The caller is expected to provide an expression of the type and it will be used by the operation as specified in the ensures clause.

Operation Sum (evaluates I, J : Integer): Integer;
     ensures: Sum = (I + J);

Main program:
     Var Num, IntSum : Integer;
     Num := 5;
     IntSum = Sum (Num + 2; Num + 6);

After Sum executes:
     Num = 5; IntSum = 18;