$pg->add_fact( gnarfle => qw/ foo bar baz / );
$pg->add_fact( gnarfle => qw/ foo tac toe / );
$pg->add_fact( gnarfle => qw/ tic tac toe / );

my $results = gnarfle( qw/ $one _ $two / );
# or
my $results = gnarfle( qw/ $one tac $two / );