10.1 Have You Found a Bug?
If you are not sure whether you have found a bug, here are some guidelines:
     
- If the assembler gets a fatal signal, for any input whatever, that is a
as bug.  Reliable assemblers never crash.
     
 - If as produces an error message for valid input, that is a bug.
     
 - If as does not produce an error message for invalid input, that
is a bug.  However, you should note that your idea of “invalid input” might
be our idea of “an extension” or “support for traditional practice”.
     
 - If you are an experienced user of assemblers, your suggestions for improvement
of as are welcome in any case.