Op::Multiplication->new( Op::Term->new(5), Op::Addition->new( Op::Term->new(6), Op::Term->new(7) ) )->display; # 5 * (6 + 7) Op::Addition->new( Op::Term->new(5), Op::Multiplication->new( Op::Term->new(6), Op::Term->new(7) ) )->display; # 5 + 6 * 7