;;;  Name:
;;;  Email:

;;; Q1.

; YOUR CODE HERE
(query (add-to-all a ((b) (c d)) ((a b) (a c d))))
; expect Success!
(query (add-to-all a ((b c) (b) (foo)) ?what))
; expect Success! ; what: ((a b c) (a b) (a foo))
(query (add-to-all ?what ((c) (d e) ()) ((b c) (b d e) (b))))
; expect Success! ; what: b
(query (add-to-all ?what ?list ((b c) (d e) (b))))
; expect Failed.

;;; Q2.

(fact (append () ?a ?a))
(fact (append (?x . ?r) ?b (?x . ?c))
      (append ?r ?b ?c))

; YOUR CODE HERE

(query (sublists (1 2 3) ?subs))
; expect Success! ; subs: (() (3) (2) (2 3) (1) (1 3) (1 2) (1 2 3))

;;; Q3.

(fact (fruits apple banana cherry date elderberry fig guava))

; YOUR CODE HERE

(query (fruits-tail date elderberry fig guava))
; expect Success!
(query (fruits-tail banana . ?after-banana))
; expect Success! ; after-banana: (cherry date elderberry fig guava)
(query (fruits-tail ?e fig guava))
; expect Success! ; e: elderberry

;;; Q4.

(fact (prefix () ?s))
(fact (prefix (?first . ?p) (?first . ?s))
      (prefix ?p ?s))

; YOUR CODE HERE

(query (fruit-range cherry guava (date elderberry fig)))
; expect Success!
(query (fruit-range cherry elderberry date))
; expect Failed.
(query (fruit-range cherry elderberry ?between))
; expect Success! ; between: (date)
(query (fruit-range cherry date ()))
; expect Failed.
(query (fruit-range banana fig ?between))
; expect Success! ; between: (cherry date elderberry)

;;; Q5.

;  sentence : optional-article noun verb optional-article noun
;  optional-article : "the" | <empty>
;  noun : "boy" | "cat"
;  verb : "carries" | "feeds"


; logic> (query (noun (boy feeds cat) (feeds cat)))
; Success!
; logic> (query (sentence (the boy feeds the cat and so forth) (and so forth)))
; Success!
; logic> (query (noun (boy cat feeds) ?r))
; Success!
; r: (cat feeds)
; logic> (query (optional-article (a boy) (boy)))
; Success!
; logic> (query (optional-article (cat feeds boy) (cat feeds boy)))
; Success!


(fact (noun (boy . ?r) ?r))
(fact (noun (cat . ?r) ?r))
(fact (verb (carries . ?r) ?r))
(fact (verb (feeds . ?r) ?r))
; YOUR CODE HERE
(query (optional-article (the boy) (boy)))
; expect Success!
(query (optional-article (cat feeds boy) (cat feeds boy)))
; expect Success!
(query (optional-article (the cat feeds boy) (cat feeds boy)))
; expect Success!
(query (optional-article (the cat feeds boy) (the cat feeds boy)))
; expect Success!
(query (optional-article (feeds boy) ?x))
; expect Success! ; x: (feeds boy)
(query (optional-article ?x (cat feeds boy)))
; expect Success! ; x: (cat feeds boy) ; x: (the cat feeds boy)
(query (sentence (the boy carries cat) ()))
; expect Success!
(query (sentence (the ?sub carries the ?obj) ()))
; expect Success! ; sub: boy	obj: boy ; sub: boy	obj: cat ; sub: cat	obj: boy ; sub: cat	obj: cat