Tic-tac-toe written in Prolog

This program is the first larger dialogical logic program I've written. It's describing a perfect play of tic-tac-toe.

Dialogical logic programming treats proof-search as a game-tree-search. This can be used to write programs that refuse to interact if it cannot be proven that there would be a desirable outcome.

The program is configured to do a perfect play, eg. Either a win or tie. If you adjust the option of tie away, it refuses to play. You may also loosen the constraints and you may make it to prevent itself from winning or disregard the outcome.

I believe that the approach of building this kind of a program can be generalised to arbitrary programs.

This program has been tested in SWI-Prolog.

How to play

?- consult('tictactoe.pro').
?- play.

Example gameplay

?- play.
...
x..
...
Available moves:[move(o,2,2),move(o,2,1),move(o,2,0),move(o,1,2),move(o,1,1),move(o,1,0),move(o,0,2),move(o,0,0)]
Give your move:
|: move(o, 1,1).
...
xo.
x..
Available moves:[move(o,2,2),move(o,2,1),move(o,2,0),move(o,1,2),move(o,1,0),move(o,0,0)]
Give your move:
|: move(o, 0, 0).
o..
xo.
x.x
Available moves:[move(o,2,1),move(o,2,0),move(o,1,2),move(o,1,0)]
Give your move:
|: move(o, 2, 0).
o.o
xo.
xxx
I won. You lose.
true.


?- play.
...
...
..x
Available moves:[move(o,2,1),move(o,2,0),move(o,1,2),move(o,1,1),move(o,1,0),move(o,0,2),move(o,0,1),move(o,0,0)]
Give your move:
|: move(o,1,1).
..x
.o.
..x
Available moves:[move(o,2,1),move(o,1,2),move(o,1,0),move(o,0,2),move(o,0,1),move(o,0,0)]
Give your move:
|: move(o,2,1).
..x
xoo
..x
Available moves:[move(o,1,2),move(o,1,0),move(o,0,2),move(o,0,0)]
Give your move:
|: move(o,1,0).
.ox
xoo
.xx
Available moves:[move(o,0,2),move(o,0,0)]
Give your move:
|: move(o,0,2).
xox
xoo
oxx
It is a tie
true.