use strict;
use warnings;

require "Constraint.pm";

my $var1 = Constraint::Var::Number->new;
my $var2 = Constraint::Var::Number->new;
my $var3 = Constraint::Var::Number->new;

my $evaluator = Constraint::Evaluator->new;

$evaluator->connect([$var1, '='], ['+', $var2], ['+', $var3]);

$var2->set(3);
$var3->set(4);

$evaluator->eval;

print $var1->get;