# The constraint is that two queens cannot be on the same row, column or diagonal.
#
# Eg. a solution to the 8-queens problem is
-# ~~~
+# ~~~raw
# +--------+
# |Q.......|
# |....Q...|
#
# This program takes an integer n as argument then display all solutions for the
# n-queens proglem (ie. on a n*n board).
-module queens
+module queens is example
import ai::backtrack