Incompatible changes .. was Re: Program stack overflow defining infix operator



On Mon, 2009-08-10 at 10:00 -0600, Robert Dodier wrote:
> On Mon, Aug 10, 2009 at 3:54 AM, Barton Willis<willisb at unk.edu> wrote:
   . . .
> OK, thanks for this info. From the user's point of view,
> I think the major distinction is commutative vs noncommutative,
> and short-circuit vs non-short-circuit.
> At present we have noncommutative, short-circuit operators.
> I think we also want commutative, non-short-circuit operators,
> among other things.

Is the primary purpose of this facility the evaluation of boolean
expressions or support for symbolic boolean algebra with "occasional"
evaluation?  If the former then short-circuit evaluation may be a good
idea but if the latter then short-circuit evaluation seems not to be so
useful.  In either case commutativity of nand, nor, and, or and iff are
important.  if-then, of course, is not commutative.

-- 
Bill Wood