i1 : y = tally {1,2,3,a,b,1,2,a,1,2,{a,b},{a,b},a} o1 = Tally{{a, b} => 2} 1 => 3 2 => 3 3 => 1 a => 3 b => 1 o1 : Tally |
i2 : y_2 o2 = 3 |
i3 : y_5 o3 = 0 |
i4 : y_{a,b} o4 = 2 |