Animals.scala

 abstract class Animal {
    def greetings {
      println("an animal")
    }
  }

  trait Mammal extends Animal {
    abstract override def greetings {
      println("I'€™m a mammal")
      super.greetings
    }
  }

  trait Carnivore extends Mammal {
    abstract override def greetings {
      println("I'€™m a carnivore")
      super.greetings
    }
  }

  trait FourLegged extends Animal {
    abstract override def greetings {
      println("I have four legs")
      super.greetings
    }
  }

  object Dog extends Carnivore with FourLegged {
    override def greetings {
      println("I'€™m a dog")
      super.greetings
    }
  }

  Dog.greetings