isDerangement -- whether a permutation is a derangement

• Usage:

  fixedPoints w

• Inputs:
  • w, a permutation,
• Outputs:
  • a Boolean value,

i1 : p = permutation {3,1,2,5,4}

o1 = Permutation{3, 1, 2, 5, 4}

o1 : Permutation

i2 : isDerangement p

o2 = true