17 Feb 2005
CS 3243 - Constraint Satisfaction
40
Special kinds of Consistency
nSome kinds
of constraint lend themselves to special kinds of arc-consistency
nConsider
the all-different constraint
nthe
named variables must all take different values
nnot
a binary constraint
ncan
be expressed as n(n-1)/2 not-equals constraints
nWe
can apply (e.g.) AC3 as usual
nBut
there is a much better option