class Proc

  def *(n)
    proc do |arg|
      input = arg
      output = nil
      n.times do
        output = self.call(input)
        input = output
      end
      output
    end
  end

end

x = proc { |n| n + 1 }

p x*5
p (x*5).call(1)

#<Proc:0x401bfa54@t.rb:4>
6