1 % Example Input
   2 % t(1,5).
   3 % t(2,3).
   4 % t(3,1).
   5 % t(4,4).
   6 % t(5,2).
   7 % p(1,2).
   8 % p(2,3).
   9 % p(3,1).
  10 % patternlength(3).
  11 
  12 % Guess suitable subsequence
  13 
  14 %1 <= { subt(K,I,E) : t(I,E) } <= 1 :- K=1..L, patternlength(L).
  15 
  16 kval(1).
  17 kval(N+1) :- kval(N), N < L, patternlength(L). 
  18 1 <= { subt(K,I,E) : t(I,E) } <= 1 :- kval(K), patternlength(L).
  19 :- subt(K1,I1,_), subt(K2,I2,_), K1<K2, I1 >= I2.
  20 
  21 solution(K,E) :- subt(K,_,E).
  22 
  23 % Check whether the subsequence is a matching
  24 :- solution(K1,ET1), solution(K2,ET2), p(K1,EP1), p(K2,EP2), ET1 < ET2, EP1 >= EP2.