#!/usr/local/bin/perl
# see http://www.compapp.dcu.ie/~alex/LOGIC/monkey.html
# This is the classic Monkey/Banana problem
use strict;
use lib ('../lib/', 'lib');
my $database = Parser->consult(<<'END_PROLOG');
perform(grasp,
state(middle, middle, onbox, hasnot),
state(middle, middle, onbox, has)).
perform(climb,
state(MP, BP, onfloor, H),
state(MP, BP, onbox, H)).
perform(push(P1,P2),
state(P1, P1, onfloor, H),
state(P2, P2, onfloor, H)).
perform(walk(P1,P2),
state(P1, BP, onfloor, H),
state(P2, BP, onfloor, H)).
getfood(state(Bogus1,Bogus2,Bogus3,has)).
getfood(S1) :- perform(Act, S1, S2),
nl, print('In '), print(S1), print(' try '), print(Act), nl,
getfood(S2).
END_PROLOG
my $parser = Parser->new("getfood(state(atdoor,atwindow,onfloor,hasnot)).");
my $query = Term->new($parser);
my $engine = Engine->new($query,$database);
Engine->formatted(1);
print $engine->results;