https://sites.google.com/site/prologsite/prolog-problems/

## Lists
[x] 1.01 (*) Find the last element of a list.
[x] 1.02 (*) Find the last but one element of a list.
[x] 1.03 (*) Find the K'th element of a list.
[x] 1.04 (*) Find the number of elements of a list.
[x] 1.05 (*) Reverse a list.
[x] 1.06 (*) Find out whether a list is a palindrome.
[x] 1.07 (**) Flatten a nested list structure.
[x] 1.08 (**) Eliminate consecutive duplicates of list elements.
[x] 1.09 (**) Pack consecutive duplicates of list elements into sublists.
[x] 1.10 (*) Run-length encoding of a list.
[x] 1.11 (*) Modified run-length encoding.
[x] 1.12 (**) Decode a run-length encoded list.
[x] 1.13 (**) Run-length encoding of a list (direct solution).
[x] 1.14 (*) Duplicate the elements of a list.
[x] 1.15 (**) Duplicate the elements of a list a given number of times.
[x] 1.16 (**) Drop every N'th element from a list.
[x] 1.17 (*) Split a list into two parts; the length of the first part is given.
[x] 1.18 (**) Extract a slice from a list.
[ ] 1.19 (**) Rotate a list N places to the left.
[ ] 1.20 (*) Remove the K'th element from a list.
[ ] 1.21 (*) Insert an element at a given position into a list.
[ ] 1.22 (*) Create a list containing all integers within a given range.
[ ] 1.23 (**) Extract a given number of randomly selected elements from a list.
[ ] 1.24 (*) Lotto: Draw N different random numbers from the set 1..M.
[ ] 1.25 (*) Generate a random permutation of the elements of a list.
[ ] 1.26 (**) Generate the combinations of K distinct objects chosen from the N elements of a list
[ ] 1.27 (**) Group the elements of a set into disjoint subsets.
[ ] 1.28 (**) Sorting a list of lists according to length of sublists.

## Arithmetic
[x] 2.01 (**) Determine whether a given integer number is prime.
[x] 2.02 (**) Determine the prime factors of a given positive integer.
[x] 2.03 (**) Determine the prime factors of a given positive integer (2).
[x] 2.04 (*) A list of prime numbers.
[x] 2.05 (**) Goldbach's conjecture.
[x] 2.06 (**) A list of Goldbach compositions.
[ ] 2.07 (**) Determine the greatest common divisor of two positive integer numbers.
[ ] 2.08 (*) Determine whether two positive integer numbers are coprime.
[ ] 2.09 (**) Calculate Euler's totient function phi(m).
[ ] 2.10 (**) Calculate Euler's totient function phi(m) (2).
[ ] 2.11 (*) Compare the two methods of calculating Euler's totient function