#                                   return value        substance
i = 3
p 1 + i                         #=> 4                   1.+(i)
p i < 5                         #=> true                i.<(5)
p 2 ** i                        #=> 8                   2.**(i)
p -i                            #=> -3                  i.-@()
a = [1,2,3]
p a[0]                          #=> 1                   a.[](0)
a[2] = "0"                      #                       a.[]=(2,"0")
p a << 5                        #=> [1, 2, "0", 5]      a.<<(5)
p a & [4,2]                     #=> [2]                 a.&([4,2])
p "abcde"[1..3]                 #=> "bcd"               "abcde".[](1..3)
p "%2d %4s" % [1,"xyz"]         #=> " 1  xyz"           "%2d %4s".%([1,"xyz"])