%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% Filename: dcglloyd.pl %% Date: 2025-04-11 %% Authors: Lloyd Sanderson %% Description: %% Provides DCG syntax to parse certain words and queries into %% tokens which are then read by the compiler and answered according to %% their respective clauses. 2 different question syntaxes are taken into %% account: Who and What. Depending on the tokens consumed in the query, it %% parses into certain question verbs and phrases, then pulls from a database, %% a list of facts that it then presents in the listener. Takes grammatical queries only %% and reject and decline ungrammatical queries. Additionally, it provides hints given %% the answer is shown as wrong when input by the user. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % Declare some predicates as discontiguous so that their clauses may be defined in non�]adjacent parts of the file. :- discontiguous plays/3. :- discontiguous directs/2. :- discontiguous title_of/2. :- discontiguous proper_noun/3. :- discontiguous question_verb/3. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% HELPER FOR RELATIONS %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% Succeeds if Actor plays Character in Movie actor_for(Character,Actor,Movie) :- plays(Actor,Character,Movie). %% Succeeds if Actor plays Character (ignoring movie) character_of(Actor,Character) :- plays(Actor,Character,_). %% Succeeds if Director directs Movie director_of(Movie,Director) :- directs(Director,Movie). %% Succeeds if Actor plays in Movie actor_in(Movie,Actor) :- plays(Actor,_,Movie). %% Succeeds if Director exists in any context is_director(Director) :- directs(Director, _). %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% TOP LEVEL %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % The top/1 predicate is the main entry point that handles queries. % It attempts to parse the input list (S) using various DCG rules (yesno/1, who/1, what/1). % It then tests the semantic query, writes an appropriate response, or prints a hint if false. % If the parsed yes/no query succeeds (test(Query) succeeds), output a positive message. top(S) :- yesno(Query, S, []), % Parse S as a yes/no query; Query is a list of semantic facts. test(Query), % Evaluate each fact in Query using test/1. !, write('Yes, that is true.'), nl, !. % If the parsed yes/no query fails (test(Query) fails), output a negative message and then produce hints. top(S) :- yesno(Query, S, []), \+ test(Query), % One or more facts in Query failed. !, write('Sorry, that is false.'), nl, hint(Query), % Process the list of facts to generate hints. !. % If the query is a Who-question, parse it with the who/1 rule and then answer. top(S) :- who(Query, S, []), !, answer_who(Query). % If the query is a What-question, parse it with the what/1 rule and then answer. top(S) :- what(Query, S, []), !, answer_what(Query). % Fallback clause if none of the above parsing rules match. top(_) :- write('I dont get it.'), nl, !. % test/1 predicate: succeeds if all elements of the list are true. test([]). test([H|T]) :- H, % Call the fact. test(T). % Recursively test the remainder of the list. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% ANSWER PREDICATES %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % answer_who/1 handles "Who" queries based on the semantic representation produced by the DCG. % It has several clauses depending on the structure of the query. % Clause for queries of the form actor_for(Character, Actor, Movie): % Retrieves a fact from plays/3, formats the names, and prints the result. answer_who(actor_for(Character, Actor, Movie)) :- plays(Actor, Character, Movie), formatname(Actor, ChangedActor), formatname(Character, ChangedCharacter), formatname(Movie, ChangedMovie), format('~w plays as ~w in ~w.', [ChangedActor, ChangedCharacter, ChangedMovie]), nl. % Clause for queries of the form actor_for(Character, Actor) (movie unspecified): answer_who(actor_for(Character, Actor)) :- plays(Actor, Character, Movie), formatname(Actor, ChangedActor), formatname(Character, ChangedCharacter), formatname(Movie, ChangedMovie), format('~w plays as ~w in ~w.', [ChangedActor, ChangedCharacter, ChangedMovie]), nl. % Clause for queries directly produced as plays/3: answer_who(plays(_, Character, Movie)) :- plays(Actor, Character, Movie), formatname(Actor, ChangedActor), formatname(Character, ChangedCharacter), formatname(Movie, ChangedMovie), format('~w plays as ~w in ~w.', [ChangedActor, ChangedCharacter, ChangedMovie]), nl. % Clause for character_of queries (Who is the character of ...?): answer_who(character_of(Actor, Character)) :- plays(Actor, Character, Movie), % The fact is derived from plays/3. formatname(Actor, ChangedActor), formatname(Character, ChangedCharacter), formatname(Movie, ChangedMovie), format('~w is the character of ~w in ~w.', [ChangedActor, ChangedCharacter, ChangedMovie]), nl. % Clause for director_of queries (Who is the director of ...?): answer_who(director_of(Movie, Director)) :- director_of(Movie, Director), formatname(Movie, ChangedMovie), formatname(Director, ChangedDirector), % The call director_of(Movie,Director) is repeated for clarity (or additional side effects), director_of(Movie, Director), format('The director of ~w is ~w.', [ChangedMovie, ChangedDirector]), nl. % Clause for actor_in queries (Who acts in ...?): answer_who(actor_in(Movie, Actor)) :- actor_in(Movie, Actor), formatname(Actor, ChangedActor), formatname(Movie, ChangedMovie), format('~w acts in ~w.', [ChangedActor, ChangedMovie]), nl. % answer_what/1 handles "What" queries (for example, "What is the title of ...?") answer_what(title_of(Movie, Title)) :- title_of(Movie, Title), formatname(Movie, ChangedMovie), format('The title of ~w is "~w".', [ChangedMovie, Title]), nl. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% DCG GRAMMAR %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % This defines DCG rules and how to parse the input (a list of tokens) into semantic representations. % yesno/1: Parses yes/no queries. yesno(Sem) --> optional_intro, statements(Sem), optional_right, [?]. yesno(Sem) --> [did], statement_past(Sem), optional_right, [?]. yesno(Sem) --> statements(Sem), optional_right, [?]. % optional_intro: Parses an optional introductory phrase like "is it true that" optional_intro --> [is, it, true, that]. % who/1: Parses queries starting with "who" followed by a question verb. who(Sem) --> [who], question_verb(Sem), [?]. % what/1: Parses "what is the title of ..." queries. what(title_of(Movie, _Title)) --> [what, is, the, title, of], proper_noun(Movie), [?]. % statement/1: Parses a statement into a list of semantic facts. statement(Fact) --> noun_phrase(Subj, _), verb_phrase(Subj, _Type, Fact). % Base case: takes on minimum one statement per call. statements([Fact]) --> statement(Fact). % Recurses through the entirety of the facts that are connected by separators to evaluate each % of the queries that are described in the token input statements([Fact|Rest]) --> statement(Fact), separator, statements(Rest). % statement_past/1: Parses past-tense statements. statement_past([Fact]) --> noun_phrase(Subj, _), verb_phrase_past(Subj, Fact). % Unnecessary coding... statement_past([Fact|Rest]) --> noun_phrase(Subj, _), verb_phrase_past(Subj, Fact), separator, statement_past(Rest). % A separator/1 predicate that separates each fact called in multi-fact sentences. % Able to parse either when input is shown as a comma or an and. separator --> [',']. separator --> [and]. separator --> [','], [and]. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% HINT SECTION (E.C)? %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % The hint/1 predicate processes a list of semantic facts (the parsed query) % and, for each fact that fails (via run_hint/1), calls hint_fact/1 to print a suggestion. hint([]). hint([Fact|Rest]) :- run_hint(Fact), hint(Rest). % run_hint/1: If a fact succeeds (call(Fact) is true), do nothing. run_hint(Fact) :- call(Fact). % Otherwise, if the fact fails, call hint_fact/1 to print a hint. run_hint(Fact) :- \+ call(Fact), hint_fact(Fact). %% --------------------------- Director Queries ------------------------------- % These clauses provide hints when a director query is misclassified. % If a query uses a director predicate but the given person is not a director % (i.e. there is no fact director_of(_, GivenDirector)) and the person appears in plays/3 as a character, % then they are misclassified. % If the director is misclassified as an actor, print out the following... % Because the below 2 hints are the same structure, the argument would need to be instantiated to % correctly choose the right clause to use. hint_fact(plays(Person, _, _)) :- \+ var(Person), % Requires the Person to be instantiated directs(Person, _), formatname(Person, ChangedPerson), format('~w is a director, not an actor.', [ChangedPerson]), nl. % If the director is misclassified as a character (AKA shown in the second argument) hint_fact(plays(_, Person, _)) :- \+ var(Person), % Requires Person to be instantiated directs(Person, _), formatname(Person, ChangedPerson), format('~w is a director, not a character.', [ChangedPerson]), nl. hint_fact(directs(GivenDirector, _Movie)) :- \+ (director_of(_, GivenDirector)), % GivenDirector is not found as a director. plays(_, GivenDirector, _), % But appears in plays/3 (as a character). formatname(GivenDirector, ChangedDirector), format('~w is a character, not a director.', [ChangedDirector]), nl. % Similar clause for director_of queries. hint_fact(director_of(_Movie, GivenDirector)) :- \+ (director_of(_, GivenDirector)), plays(_, GivenDirector, _), formatname(GivenDirector, ChangedDirector), format('~w is a character, not a director.', [ChangedDirector]), nl. % If the movie is specified (nonvar(Movie)) in a directs/2 query, % then look up the correct director and suggest the correct answer. hint_fact(directs(GivenDirector, Movie)) :- \+ var(Movie), director_of(Movie, CorrectDirector), GivenDirector \= CorrectDirector, formatname(CorrectDirector, ChangedDirector), formatname(Movie, ChangedMovie), format('You might be looking for ~w who directed ~w.', [ChangedDirector, ChangedMovie]), nl. % If no movie is specified (var(Movie)), and the given director appears in plays/3, % then indicate the person is actually an actor. hint_fact(directs(GivenDirector, Movie)) :- var(Movie), plays(GivenDirector, _, _), formatname(GivenDirector, ChangedDirector), format('~w is an actor, not a director.', [ChangedDirector]), nl. % Similar hint for director_of/2 queries. hint_fact(director_of(Movie, GivenDirector)) :- director_of(Movie, CorrectDirector), GivenDirector \= CorrectDirector, formatname(CorrectDirector, ChangedDirector), formatname(Movie, ChangedMovie), format('You might be looking for ~w who directed ~w.', [ChangedDirector, ChangedMovie]), nl. %% ----------------------- Actor vs. Character Misclassification ----------------------- % If a query is parsed as an actor query (plays(Person,_,_)) but the given person % never appears as an actor (first argument) and does appear as a character (second argument), % then the person is really a character. hint_fact(plays(Person, _, _)) :- \+ plays(Person, _, _), plays(_, Person, _), formatname(Person, ChangedPerson), format('~w is a character, not an actor or director.', [ChangedPerson]), nl. % If a query is parsed as a character query (plays(_, Person, _)) but the given person % does appear as an actor (first argument), then the person is actually an actor. hint_fact(plays(_, Person, _)) :- plays(Person, _, _), formatname(Person, ChangedPerson), format('~w is an actor, not a character.', [ChangedPerson]), nl. %% ---------------------------- Actor Query Hints ------------------------------------- % If the query is of the form actor_for(Character, GivenActor, Movie) % and the CorrectActor (from actor_for/3) is different than the GivenActor, % then suggest the correct actor hint_fact(actor_for(Character, GivenActor, Movie)) :- actor_for(Character, CorrectActor, Movie), GivenActor \= CorrectActor, formatname(CorrectActor, ChangedActor), formatname(Character, ChangedCharacter), formatname(Movie, ChangedMovie), format('You might be looking for ~w who plays ~w in ~w.', [ChangedActor, ChangedCharacter, ChangedMovie]), nl. %% Similarly for actor_for(Character, GivenActor) without specified movie hint_fact(actor_for(Character, GivenActor)) :- actor_for(Character, CorrectActor, Movie), GivenActor \= CorrectActor, formatname(CorrectActor, ChangedActor), formatname(Character, ChangedCharacter), formatname(Movie, ChangedMovie), format('You might be looking for ~w who played ~w in ~w.', [ChangedActor, ChangedCharacter, ChangedMovie]), nl. %% If the query produces a plays/3 semantic term for an actor query % then use actor_for/3 to provide the correct answer hint_fact(plays(_, Character, Movie)) :- actor_for(Character, CorrectActor, Movie), formatname(CorrectActor, ChangedActor), formatname(Character, ChangedCharacter), formatname(Movie, ChangedMovie), format('You might be looking for ~w who played ~w in ~w.', [ChangedActor, ChangedCharacter, ChangedMovie]), nl. %% --------------------------- Movie Relation -------------------------------- %% If the given query specifies a movie for the character, but the fact is not found for that movie % then look up the correct movie for that character hint_fact(plays(_, Character, Movie)) :- \+ plays(_, Character, Movie), % No fact for the character in the queried Movie plays(_, Character, CorrectMovie), % There is a fact for character in the correct movie CorrectMovie \= Movie, % And its different from the queried movie formatname(Character, ChangedCharacter), formatname(CorrectMovie, ChangedMovie), format('~w is a character in ~w.', [ChangedCharacter, ChangedMovie]), nl. %% ---------------- Character Related hints ----------------- %% For queries of the form character_of(Actor,GivenActor) % if the CorrectCharacter (from character_in/2) is different from the GivenCharacter % then provide the correct character from the given fact hint_fact(character_of(Actor, GivenCharacter)) :- character_of(Actor, CorrectCharacter), GivenCharacter \= CorrectCharacter, formatname(Actor, ChangedActor), formatname(CorrectCharacter, ChangedCharacter), format('You might be looking for ~w, who is the character of ~w.', [ChangedCharacter, ChangedActor]), nl. %% ------------------ Actor_in Query Hint ------------------- % For queries of the form actor_in(Movie, GivenActor) % If the CorrectActor (from actor_in/2) is different from the GivenActor % Then suggest the correct one hint_fact(actor_in(Movie, GivenActor)) :- actor_in(Movie, CorrectActor), GivenActor \= CorrectActor, formatname(CorrectActor, ChangedActor), formatname(Movie, ChangedMovie), format('You might be looking for ~w who acted in ~w.', [ChangedActor, ChangedMovie]), nl. %% Fallback: If nothing matches do nothing hint_fact(_) :- true. %%---------------------------------------------------------------------------- %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% PHRASE CONSTRUCTION %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % noun_phrase/2: Builds a noun_phrase for a given actor, character, or a director noun_phrase(Name, actor) --> proper_noun(Name). noun_phrase(Name, director) --> proper_noun(Name). noun_phrase(Name, character) --> proper_noun(Name). % verb_phrase/3: builds a verb_phrase connecting a subject (Subj) to a fact % The second argument (Type) distinguishes whether it is a actor, character, or director verb_phrase(Subj, actor, plays(Subj,_,_)) --> [is,an,actor]. verb_phrase(Subj, character, plays(_,Subj,_)) --> [is,a,character]. verb_phrase(Subj, character, plays(_,Subj,Movie)) --> [is,a,character,in], proper_noun(Movie). verb_phrase(Subj, director, directs(Subj, _)) --> [is,a,director]. % For actor queries with "plays as" or "is the actor for" a given character verb_phrase(_, actor, actor_for(Character,_Actor)) --> ( [plays,as] ; [is,the,actor,for] ), proper_noun(Character). verb_phrase(_, actor, actor_for(Character,_Actor,Movie)) --> ( [plays,as] ; [is,the,actor,for] ), proper_noun(Character), [in], proper_noun(Movie). % For generic plays/3 queries verb_phrase(Subj, _, plays(Subj,Character,_)) --> [plays], proper_noun(Character). verb_phrase(Subj, _, plays(Subj,Character,Movie)) --> [plays], proper_noun(Character), [in], proper_noun(Movie). % For generic director queries verb_phrase(Subj, _, directs(Subj,Obj)) --> [directs], proper_noun(Obj). % For character_of queries verb_phrase(_, character, character_of(Actor,_Character)) --> [is,the,character,of], proper_noun(Actor). % director_of queries verb_phrase(_, director, director_of(Movie,_Director)) --> [is,the,director,of], proper_noun(Movie). % actor_in queries verb_phrase(_, actor, actor_in(Movie,_Actor)) --> [acts,in], proper_noun(Movie). % verb_phrase_past/2: Builds a past-tense verb_phrase (e.g. "play" instead of "plays") verb_phrase_past(Subj, plays(Subj,Character,Movie)) --> [play], proper_noun(Character), [in], proper_noun(Movie). verb_phrase_past(Subj, plays(Subj,Character,_)) --> [play], proper_noun(Character). verb_phrase_past(Subj, directs(Subj,Obj)) --> [direct], proper_noun(Obj). % For questions that use directs so that the resulting semantic term matches the answer_who phrase question_verb(director_of(Movie, _)) --> [directs], proper_noun(Movie). % Allows for the usage of a "right" at the end of a statement, takes with a comma, or just by itself optional_right --> separator, [right]. optional_right --> [right]. optional_right --> []. % question_verb/1: Parses a question verb phrase question_verb(Sem) --> verb_phrase(_,_,Sem). %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% LEXICON (Proper Nouns) %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% proper_noun/1: Parses multi-word proper names into atoms. proper_noun(mark_hamill) --> [mark,hamill]. proper_noun(harrison_ford) --> [harrison,ford]. proper_noun(carrie_fisher) --> [carrie,fisher]. proper_noun(liam_neeson) --> [liam,neeson]. proper_noun(natalie_portman) --> [natalie,portman]. proper_noun(jake_lloyd) --> [jake,lloyd]. proper_noun(ian_mcdiarmid) --> [ian,mcdiarmid]. proper_noun(ewan_mcgregor) --> [ewan,mcgregor]. proper_noun(hayden_christensen) --> [hayden,christensen]. proper_noun(christopher_lee) --> [christopher,lee]. proper_noun(samuel_l_jackson) --> [samuel,l,jackson]. proper_noun(alec_guinness) --> [alec,guinness]. proper_noun(peter_cushing) --> [peter,cushing]. proper_noun(jimmy_smits) --> [jimmy,smits]. proper_noun(frank_oz) --> [frank,oz]. proper_noun(kenny_baker) --> [kenny,baker]. proper_noun(george_lucas) --> [george,lucas]. proper_noun(star_wars_i) --> [star,wars,i]. proper_noun(star_wars_ii) --> [star,wars,ii]. proper_noun(star_wars_iii) --> [star,wars,iii]. proper_noun(star_wars_iv) --> [star,wars,iv]. proper_noun(qui_gon_jinn) --> [qui,gon,jinn]. proper_noun(luke_skywalker) --> [luke,skywalker]. proper_noun(han_solo) --> [han,solo]. proper_noun(princess_leia) --> [princess,leia]. proper_noun(padme_amidala) --> [padme,amidala]. proper_noun(obi_wan_kenobi) --> [obi,wan,kenobi]. proper_noun(anakin_skywalker) --> [anakin,skywalker]. proper_noun(palpatine) --> [palpatine]. proper_noun(count_dooku) --> [count,dooku]. proper_noun(mace_windu) --> [mace,windu]. proper_noun(grand_moff_tarkin) --> [grand,moff,tarkin]. proper_noun(bail_organa) --> [bail,organa]. proper_noun(r2d2) --> [r2d2]. proper_noun(yoda) --> [yoda]. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% NAME FORMAT %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% Maps internal atom names to nicely formatted strings formatname(mark_hamill, 'Mark Hamill'). formatname(harrison_ford, 'Harrison Ford'). formatname(carrie_fisher, 'Carrie Fisher'). formatname(liam_neeson, 'Liam Neeson'). formatname(natalie_portman, 'Natalie Portman'). formatname(jake_lloyd, 'Jake Lloyd'). formatname(ian_mcdiarmid, 'Ian McDiarmid'). formatname(ewan_mcgregor, 'Ewan McGregor'). formatname(hayden_christensen, 'Hayden Christensen'). formatname(christopher_lee, 'Christopher Lee'). formatname(samuel_l_jackson, 'Samuel L. Jackson'). formatname(alec_guinness, 'Alec Guinness'). formatname(peter_cushing, 'Peter Cushing'). formatname(jimmy_smits, 'Jimmy Smits'). formatname(frank_oz, 'Frank Oz'). formatname(kenny_baker, 'Kenny Baker'). formatname(george_lucas, 'George Lucas'). formatname(star_wars_i, 'Star Wars I'). formatname(star_wars_ii, 'Star Wars II'). formatname(star_wars_iii, 'Star Wars III'). formatname(star_wars_iv, 'Star Wars IV'). formatname(qui_gon_jinn, 'Qui-Gon Jinn'). formatname(luke_skywalker, 'Luke Skywalker'). formatname(anakin_skywalker, 'Anakin Skywalker'). formatname(han_solo, 'Han Solo'). formatname(princess_leia, 'Princess Leia'). formatname(padme_amidala, 'Padme Amidala'). formatname(obi_wan_kenobi, 'Obi Wan Kenobi'). formatname(palpatine, 'Palpatine'). formatname(count_dooku, 'Count Dooku'). formatname(mace_windu, 'Mace Windu'). formatname(grand_moff_tarkin, 'Grand Moff Tarkin'). formatname(bail_organa, 'Bail Organa'). formatname(yoda, 'Yoda'). formatname(r2d2, 'R2-D2'). %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% DATABASE (Facts) %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % Episode I plays(liam_neeson, qui_gon_jinn, star_wars_i). plays(ewan_mcgregor, obi_wan_kenobi, star_wars_i). plays(natalie_portman, padme_amidala, star_wars_i). plays(jake_lloyd, anakin_skywalker, star_wars_i). plays(ian_mcdiarmid, palpatine, star_wars_i). directs(george_lucas, star_wars_i). title_of(star_wars_i, 'The Phantom Menace'). % Episode II plays(ewan_mcgregor, obi_wan_kenobi, star_wars_ii). plays(natalie_portman, padme_amidala, star_wars_ii). plays(hayden_christensen, anakin_skywalker, star_wars_ii). plays(christopher_lee, count_dooku, star_wars_ii). plays(samuel_l_jackson, mace_windu, star_wars_ii). directs(george_lucas, star_wars_ii). title_of(star_wars_ii, 'Attack of the Clones'). % Episode III plays(hayden_christensen, anakin_skywalker, star_wars_iii). plays(jimmy_smits, bail_organa, star_wars_iii). plays(frank_oz, yoda, star_wars_iii). plays(kenny_baker, r2d2, star_wars_iii). plays(ewan_mcgregor, obi_wan_kenobi, star_wars_iii). directs(george_lucas, star_wars_iii). title_of(star_wars_iii, 'Revenge of the Sith'). % Episode IV plays(mark_hamill, luke_skywalker, star_wars_iv). plays(harrison_ford, han_solo, star_wars_iv). plays(carrie_fisher, princess_leia, star_wars_iv). plays(alec_guinness, obi_wan_kenobi, star_wars_iv). plays(peter_cushing, grand_moff_tarkin, star_wars_iv). directs(george_lucas, star_wars_iv). title_of(star_wars_iv, 'A New Hope').