Part A: 
  Gradually build up a program that generates all permutations

> minizinc perm0.mzn -D"n = 3" -a
> minizinc perm1.mzn -D"n = 3" -a
> minizinc perm2.mzn -D"n = 3" -a
> minizinc perm3.mzn -D"n = 3" -a

NOTE: can replace minizinc with mzn-gecode
      use of -a to get all solutions
      use of -s for stats

Part B:
  Produce a permutation without allDifferent, using channeling

>mzn-gecode permN -D"n = 3" -a


Part C:
  Take as input integers n and r and output all r-combinations of integers 1 to n

> mzn-gecode comb.mzn -D"n=5;r=2;" -a


Part D:
  Take as input integers n and r and output all r-permutations of integers 1 to n

> mzn-gecode perm-N-R.mzn -D"n=4;r=3;" -a

see sample outputs

Patrick