/* Learning last/2 - finding the last element of a list */
/* Depending on the background knowledge used two definitions can
   be found - with and without conc/2 */

background([last/2, /*conc/3,*/ components/3]).  /* without conc/3 */
propositional([[]]).

/* Examples of the target predicate */
last(b,'[b]').
last(b,'[a,b]').
last(c,'[a,b,c]').
last(c,'[a,c]').
last(c,'[b,c]').
last(c,'[c]').

/* Background knowledge */
conc([],'[a,b,c]','[a,b,c]').
conc('[a]','[b,c]','[a,b,c]').
conc('[a,b]','[c]','[a,b,c]').
conc('[a,b,c]',[],'[a,b,c]').
conc([],'[a,b]','[a,b]').
conc('[a]','[b]','[a,b]').
conc('[a,b]',[],'[a,b]').
conc([],'[b,c]','[b,c]').
conc('[b]','[c]','[b,c]').
conc('[b,c]',[],'[b,c]').
conc([],'[a,c]','[a,c]').
conc('[a]','[c]','[a,c]').
conc('[a,c]',[],'[a,c]').
conc([],'[a]','[a]').
conc('[a]',[],'[a]').
conc([],'[b]','[b]').
conc('[b]',[],'[b]').
conc([],'[c]','[c]').
conc('[c]',[],'[c]').
conc([],[],[]).

components('[a,b,c]',a,'[b,c]').
components('[a,b]',a,'[b]').
components('[b,c]',b,'[c]').
components('[a,c]',a,'[c]').
components('[a]',a,[]).
components('[b]',b,[]).
components('[c]',c,[]).