err4.rb

        def a
          yield 3
        end

def b
        arr = []
        x = 1
        1.times {
          y = 2
          arr << x
          x = 3
          a {
            arr << y
            y = 4
            arr << x
            x = 5
          }
          arr << y
          arr << x
          x = 6
        }
        arr << x
        p arr
end

100.times { b }