foo.p6

package Robots {
    class Robot   { has $.power-level }

}

package Heroes {
    class Hero    { has $.level }

    proto sub infix:<+>(|) is export {*}
    multi sub infix:<+>(Hero $a, $b) { $a.level + $b       }
    multi sub infix:<+>($a, Hero $b) { $b.level + $a       }
}

package Villains {
    class Villain { has $.evil-power }

    proto sub infix:<+>(|) is export {*}
    multi sub infix:<+>(Villain $a, $b) { $a.evil-power + $b  }
    multi sub infix:<+>($a, Villain $b) { $b.evil-power + $a  }
}

multi sub infix:<+>(Robots::Robot $a, $b) { $a.power-level + $b }
multi sub infix:<+>($a, Robots::Robot $b) { $b + $a }

say Robots::Robot.new(power-level => 3333) + Robots::Robot.new(power-level => 3333) + Heroes::Hero.new(level => 3333) + Villains::Villain.new(evil-power => 3333);