7 Jan
2008
7 Jan
'08
4:38 p.m.
Peter Verswyvelen wrote:
Jerzy wrote:
The relational syntax of Prolog is more "universal" than the functional notation, since you have logic variables and logical-non-determinism, and
Isn't this just because mathematically, a function *is* a relation, but not vice versa? A relation being just a subset of a Cartesian product of sets, while a function being a special kind of relation for which each element in the domain has exactly one image? So relations are inherently much more universal than functions, but they are not that practical to work with (for a computer and/or human?).
You can as well regard a relation as a special sort of function, i.e. define relation ~ as a function A x B -> Bool by (a,b) |-> a ~ b. Cheers Ben