At=Struct.new(:a, :al, :b) do
  def +(other)
    At.new(
      self.a + other.a,
      self.al + other.al,
      self.b + other.b
    )
  end
end

alph = At.new(4.0, 3.0, 1.0)
blph = At.new(6.0, 3.0, 1.0)

clph = alph + blph