Tally ** Tally

x ** y -- produces the Cartesian product of two tallies.

One of the arguments may be a Set.

     i1 = x = tally {a,a,b}
     
     o1 = tally {2 : a, 1 : b}
     
     o1 : Tally

     i2 = y = tally {1,2,2,2}
     
     o2 = tally {1 : 1, 3 : 2}
     
     o2 : Tally

     i3 = x ** y
     
     o3 = tally {2 : a,1, 6 : a,2, 1 : b,1, 3 : b,2}
     
     o3 : Tally