Relates to calls:
frontstr
prolog_main():-
searchstring("blablablablablablablathiefblablablablabla","thief",POSITION),
write("We have got a thief in ",POSITION," position"),nl,
POS=POSITION-1,
frontstr(POS,"blablablablablablablathiefblablablablabla",FRONT,REST),
write(FRONT),nl,
write(REST),nl,
searchstring(REST,"bla",POSITION1),
POS11=POSITION1-1,
frontstr(POS11,REST,THIEF,BLA),
concat(FRONT,BLA,RESULT),
write("We extracted thief from the string and the result is: ",RESULT),
nl.