> In E6, Damian write: "A junction is a single scalar value that can act like > two or more values at once". > > Whenever I see a statement like this, I tend ask myself "What happenned to > zero and one?". Perhaps its intentional; perhaps its sloppy writing. What > issues arise with junctions of 0 or 1 members?
[snip] > So is a junctions of zero and one elements valid? Abjunctions don't seem to > have any problems with the concept. See Damian's reply to "Perl 6 and Set Theory" for all the formal logical operations. http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&oe=UTF-8&safe=off&selm=3DF2FE76.6050602%40conway.org&rnum=2 I'll explain here by example: if $something > any() { "Never executed" } if $something > all() { "Always executed" } if $something > one() { "Never executed" } if $something > none() { "Always executed" } That has to do with whether the selector is universal or existential. Basically, for any() and one(), there don't exist any elements to make the hypothesis true. For all() and none(), there don't exist any elements to refute the hypothesis. For each one of these except none(), a junction of one element is exactly equivalent to that single element itself (plus the junctive operations). Luke > > Dave.
