Thu Mar 19 09:42 1987  expr.p:
E 14 - Constant string too long
E 15 - Left operand of and must be Boolean, not set
E 16 - Cannot mix sets with integers and reals as operands of *
E 17 - files may not participate in comparisons
E 18 - pointers and integers cannot be compared - operator was <=
E 19 - Strings not same length in = comparison
E 20 - scalars and Booleans cannot be compared - operator was =
e 21 - Input is used but not defined in the program statement
In program x:
  w - constant green is never used
  w - constant blue is never used
  w - variable B is used but never set
