Arithmetic and Lists

Due:

5:00am, Wednesday November 6, 2024

Description

Write a Prolog file named p3.pl that defines the following predicates:

• factorial(N, Result) – compute the factorial of a number N and place it in Result. You can assume that N is a non-negative number. For example:

  ?- factorial(0, Result).
  Result = 1 ;
  false.
  
  ?- factorial(5, Result).
  Result = 120 ;
  false.
  
  ?- factorial(5, 120).
  true ;
  false.

• assoc(Property, List, Value) – List is an association list of property value pairs. If the Property is found as the first one of the pairs in List, then Value is assigned the second of that pair. For example,

  ?- assoc(age,[],V).
  false.
  
  ?- assoc(two,[[one,1],[two,2]],V).
  V = 2 ;
  false.
  
  ?- assoc(two,[[one,1],[two,2],[one,ichi]],V).
  V = 2 ;
  false.
  
  ?- assoc(one,[[one,1],[two,2],[one,ichi]],V).
  V = 1 ;
  V = ichi ;
  false.
  
  ?- assoc(P,[[one,1],[two,2],[one,ichi]],ichi).
  P = one ;
  false.

• nth(N, List, Elt) – place the Nth element of List in Elt. For example,

  ?- nth(1, [a,b,c], Elt).
  Elt = b ;
  false.
  
  ?- nth(5, [a,b,c], Elt).
  false.
  
  ?- nth(2, [a,b,c], b).
  false.
  
  ?- nth(2, [a,b,c], c).
  true ;
  false.

  Note that nth starts at zero. You may assume that the first argument is a non-negative integer, the second argument is a possibly empty list, and the third argument is an atom or variable.

Additionally, there is a program named escape_room.pl in the starter code. Augment this program with a new predicate escape(State, Actions) where Actions will be instantiated with the list of actions to achieve the goal. For example

?- escape( state(atdoor, onfloor, middle, trapped), A).
A = [walk(atdoor, middle), push(middle, atwindow), climb, climb]

Turning in the Assignment

To submit your assignment, create a zip file named p3.zip of a DIRECTORY named p3 containing the following files:

• p3.pl
• escape_room.pl

Then submit that file to the appropriate folder on D2L.