[tutor] Update assignment

examples/basics/arithmetics.pl

@@ -0,0 +1,30 @@
+name(     character(Name,     _,     _,  _), Name).
+class(    character(   _, Class,     _,  _), Class).
+level(    character(   _,     _, Level,  _), Level).
+hitpoints(character(   _,     _,     _, HP), HP).
+
+levelup(character(Name, Class, Level, HP), character(Name, Class, Next, HP)) :-
+    succ(Level, Next).
+
+aid(character(Name, Class, Level, HP), character(Name, Class, Level, T)) :-
+    T is HP+5.
+
+hit(character(Name, Class, Level, HP), character(Name, Class, Level, T)) :-
+    T is HP-5.
+
+status(character(Name, Class, Level, HP)) :-
+    write(Name), write(' is a level '), write(Level), write(' '), write(Class), write(' with '), write(HP), write(' hitpoints.'), nl.
+
+:- initialization(main).
+
+main :-
+    Gimli = character(gimli, fighter, 4, 35), status(Gimli),
+    Legolas = character(legolas, ranger, 5, 30), status(Legolas),
+    Gandalf = character(gandalf, wizard, 10, 25), status(Gandalf),
+    Frodo = character(frodo, rogue, 2, 20), status(Frodo),
+    write('legolas threw gimli, and gimli took 5 damage.'), nl,
+    hit(Gimli, Thrown), status(Thrown),
+    write('gandalf casts aid.'), nl,
+    aid(Thrown, Aided), status(Aided),
+    write('legolas leveled up.'), nl,
+    levelup(Legolas, Leveled), status(Leveled).

examples/basics/backtracking.pl

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+leq(0, _).
+leq(s(X), s(Y)) :- leq(X, Y).
+
+:- initialization(main).
+
+main :-
+    leq(X, s(s(s(0)))),
+    write(X), nl,
+    fail.

examples/basics/cut.pl

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+leq(0, _).
+leq(s(X), s(Y)) :- leq(X, Y).
+
+:- initialization(main).
+
+main :-
+    leq(X, s(s(s(0)))), !,
+    write(X), nl,
+    fail.

examples/basics/disjunction.pl

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+likes(alice, pizza).
+likes(alice, pasta).
+likes(bob, pasta).
+
+likes_italian_food(Person) :-
+    likes(Person, pizza) ;
+    likes(Person, pasta).
+
+:- initialization(main).
+
+main :-
+    likes_italian_food(alice),
+    write('Alice likes Italian food.'), nl,
+    likes_italian_food(bob),
+    write('Bob likes Italian food.'), nl.

examples/basics/equality.pl

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+check_equal(X, Y) :-
+    X = Y,
+    write('X = Y succeeded'), nl.
+
+check_identical(X, Y) :-
+    X == Y, !,
+    write('X == Y succeeded'), nl.
+
+check_identical(_, _) :-
+    write('X == Y failed'), nl.
+
+:- initialization(main).
+
+main :-
+    check_identical(A, 13),
+    check_equal(A, 13),
+    check_identical(A, 13),
+    check_equal(42, 42),
+    check_identical(42, 42).
+

examples/basics/forall.pl

@@ -0,0 +1,11 @@
+likes(alice, pizza).
+likes(alice, pasta).
+likes(bob, pasta).
+
+:- initialization(main).
+
+main :-
+    forall(likes(X, pizza), X = alice),
+    write('Only alice likes pizza.'), nl,
+    forall(likes(X, pizza), X = bob),
+    write('Bob should not like pizza.'), nl.

examples/basics/fraternity.pl

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+age(robespierre, 25).
+age(danton, 29).
+age(marat, 35).
+age(camus, 22).
+age(desmoulins, 19).
+
+eligible_for_event(Person) :-
+    age(Person, Age),
+    between(20, 30, Age).
+
+:- initialization(list_eligible_members).
+
+list_eligible_members :-
+    eligible_for_event(Person),
+    write('Citizen '), write(Person), write(' is eligible for the event.'), nl,
+    fail.
+

examples/basics/liberty.pl

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+:- dynamic declaration/1.
+
+add_declaration_first(NewDecl) :-
+    asserta(declaration(NewDecl)).
+
+add_declaration_last(NewDecl) :-
+    assertz(declaration(NewDecl)).
+
+database :-
+    add_declaration_first('Man is born free, and everywhere he is in chains.'),
+    retract(declaration(_)),
+    add_declaration_last('The revolution devours its own children.'),
+    add_declaration_first('I disapprove of what you say, but I will defend to the death your right to say it.'),
+    add_declaration_first('Give me Liberty, or give me Death!'),
+    add_declaration_last('So this is how liberty dies, with thunderous applause.').
+
+show_declarations :-
+    declaration(Decl),
+    write(Decl), nl,
+    fail.
+
+show_declarations.
+
+:- initialization(main).
+
+main :-
+    database,
+    show_declarations,
+    retractall(declaration(_)),
+    show_declarations.
+

examples/basics/unification.pl

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+grade(alice, a).
+grade(bob, b).
+grade(carol, a).
+grade(dave, c).
+
+got_an_a(Student) :-
+    grade(Student, Grade),
+    Grade = a.
+
+did_not_get_an_a(Student) :-
+    grade(Student, Grade),
+    Grade \= a.
+
+:- initialization(main).
+
+main :-
+    write("While "),
+    got_an_a(X),
+    write(X), write(" got an A, "), fail;
+    write("but "),
+    did_not_get_an_a(Y),
+    write(Y), write(" did not get an A, "), fail; write("unfortunately."), nl.

examples/basics/write.pl

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+:- initialization(main). main :- write('gpl zegt: '), groet(wereld), nl. groet(X) :- write(dag(X)).