    # File lib/facets/more/quaternion.rb, line 350
      def + (other)
        if other.kind_of?(Quaternion)
          Quaternion(@re+other.re,@im+other.im,@jm+other.jm,@km+other.km)
        elsif other.kind_of?(Complex)
          Quaternion(@re+other.real,@im+other.image, @jm, @km)
        elsif Complex.generic?(other)
          Quaternion(@re+other.real,@im, @jm, @km)
        else x , y = other.coerce(self); x + y
        end
      end