Tally - Tally -- difference of tallies

• Operator: -

• Usage:

  x - y

• Inputs:
  • x, a tally
  • y, a tally
• Outputs:
  • a tally, the difference of the two tallies

i1 : tally {a,a,b,c} - tally {c,d,d}

o1 = Tally{a => 2}
           b => 1

o1 : Tally