CPSC 312 2017 - Midterm #2 - Variant #A (you can tell which variant
you did from question 1)

Question 1

(a) Foo Inc published a book "Prolog is Fun Book"
Foo Inc is a publisher.

(b)  The most important part is you need to create a new individual.
prop(cs3121012017,course,cs312).
prop(cs3121012017,section,101).
prop(cs3121012017,year,2017).
prop(cs3121012017,final_month,december).
prop(cs3121012017,final_day,20).


(a) A URI is a constant that has a well-defined and standard
meaning. It is useful because everyone who uses the constant means the
same thing.  (It does not imply that there is a unique URI for each
thing (the unique names assumption); there can be multiple URIs for
the same thing.)



Question 2

(a) Does not unify as I cannot be both prolog and [twists,minds]

(b) {A / h(b, Z), B / b, Y / f(h(b, Z))}

(c) {A / [c, s, i, s, f, u, n], B / [f, u, n], C / [i, s, f, u, n]}

Question 3

yes(R,I,C) :- mp([next,to, brazil],R,I,C,[]).
yes(R,I,C) :- reln([next,to,brazil],L11,I,O12,C,C12), noun(L11,R,O12,C12,[]).
yes(R,I,[next_to(I,O12)|C12]) :- noun([brazil],R,O12,C12,[]).
yes([],I,[next_to(I,brazil)]) :- country(brazil).
yes([],I,[next_to(I,brazil)]) :-.

Answer is R=[], C=[next_to(I,brazil)]

Question 4

% Tree to list (with append)
to_list(leaf,[]).
to_list(node(LT,Root,RT),L):-
    to_list(LT,L0),
    to_list(RT,L1),
    append(L0,[Root|L1],L).

% Tree to list (without append, using difference lists)
to_list_dl(T,L) :-
    tree_to_list(T,L,[]).

tree_to_list(leaf, L, L).
tree_to_list(node(LT,Root,RT),L0,L2):-
    tree_to_list(LT,L0,[Root|L1]),
    tree_to_list(RT,L1,L2).



Question 5

3rd clause should combine different list in other order

Old:

revFlat([[A|B]|T],R0,R2) :-
    revFlat([A|B],R0,R1),
    revFlat(T,R1,R2).

Should be:
revFlat([[A|B]|T],R0,R2) :-
    revFlat([A|B],R1,R2),
    revFlat(T,R0,R1).

Note that just changing the order of the clauses in the body does not help!