© 2000 Todd Neller.  A.I.M.A. text figures © 1995 Prentice Hall.  Used by permission.
Pruning Example
?
1
1
2
0
1
2
3
4
5
MAX
MIN
1 £ ? £ 4
-4 £ ? £ 1
1 £ ? £ 0
Contradiction!