coppro wrote: > Ed Murphy wrote: >> coppro wrote: >> >>> 6. NEED NOT: Failing to perform the described action does not >>> violate the rule in question. >> Note that this has a similar quirk to MAY. Consider: >> >> Rule 5001, Power=1: X MAY NOT Y. >> Rule 5002, Power=2: X MAY Y. >> >> Rule 5003, Power=1: X SHALL Z. >> Rule 5004, Power=2: X NEED NOT Z. >> >> In each pair, the Power=2 rule fails to take precedence, because the >> formal definitions don't conflict in the way that the ordinary-language >> definitions would. (Fixing this would require amending MAY and NEED >> NOT by replacing "does not violate the rule in question" with "does >> not violate the rules". I'm pretty sure I proposed this for MAY a >> while back, but don't remember what happened.) > Better to amend MMI so that it generally obeys precedence, I think, > otherwise most offences will be violations of MMI.
MMI just provides standard definitions; the rules using those definitions are evaluated according to precedence. The issue with MAY (and thus NEED NOT, which parallels it) is that precedence is only evaluated when a conflict occurs, and the above examples don't create the conflicts that you would intuitively expect; this becomes clear when you expand the definitions: 5001 (Power=1) X performing Y violates 5001. 5002 (Power=2) X performing Y does not violate 5002. Now if 5002 expanded to "X performing Y does not violate the rules", then it would conflict with and trump 5001. (The problem is one-way; if 5001 was changed to Power=3, then it would effectively trump 5002, whether through non-conflict or through conflicting-and-winning.)
