r flag   String Resolution.  Flag is a three bit number, the
         bits representing:
              4    - conditional resolution.
              2    - first destination present.
              1    - second destination present.

         The resolution sets the condition code to true for
         successful resolution, and false for failure.
         The various operands are on the top of the stack.

         e.g.      S -> A.(B).C        @s@a@b@c r3

                   S -> A.(B)          @s@a@b r1

                   stop if S -> (B).C  @s@b@c r5k4s:4


l tag    Language Flag (current values)

              1    IMP
              2    ALGOL 60
              3    PASCAL
              4    SIMULA
              5    FORTRAN

m         Call Monitor (for diagnostics)

             This is a no-op if run-time diagnostics are not
          provided.

c op      Stack condition.

             This is similar to '?' except that the resulting
          condition-code is tested by 'op' and a suitable
          value is stacked depending on the truth of the
          comparison (0 for TRUE and -1 (\0) for FALSE, for
          example).  The values of 'op' are =, #, <, >, (,
          and ) as described under CONDITIONAL BRANCHES.

          e.g.  BOOL := A=B

          @bool@a@b c= S















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