CSE341 – Homework #4- flights between cities in Turkey

Description

CSE341 – Programming Languages (Fall 2019)
Homework #4

Part 1. In the graph below you see the possible flights between some of the cities in Turkey. Write the predicate “route(X,Y) – a route between X and Y exists” that returns true of if there is a route between any given two cities.
Your program should have all the facts and predicates/rules. See the following:
% knowledge base
…
flight(istanbul,antalya). % the fact that Istanbul and Antalya has a flight.
…
% rules
…
route(X,Y) :- flight(X,Y). % a predicate indicating there exist a route between
% X and Y if there is flight between X and Y.
…
Istanbul
Ankara
Van
Izmir
Ri
ze
Antalya
Gaziantep
Konya
Edirne
Edremit
Erzincan
Ispa
rta
Burdur
A single query to complete your program should check if there is a direct route between two given cities. Alternatively, it can list all the connected cities for a given city. See the following:
?- route(edirne,X).
X = erzincan ;
X = edremit ;
Make sure that your predicate implementation handles cycles properly avoiding infinite loops.
Part 2. Continuing with the previous problem, you are asked to write a program that checks if a route exists between two cities and if so, provides the shortest route.
In the first step, you are to expand the knowledge by adding distances for the direct flights. E.g.,
% knowledge base
…
flight(istanbul, antalya). % the fact that Istanbul and Antalya has a flight.
distance(istanbul, antalya, 481). % flight distance – calculated using
% https://www.distancecalculator.net
% complete all the flights and distances …
…
A single query to complete your program should check if there is a direct route between two given cities and the shortest distance between them. See the following example:
?- sroute(edremit,erzincan,X).
X = 1044 ;
Part 3. You are given the following database about classes, classrooms and student enrollment.

Classes

Enrollment

Write the predicates “when(X,Y) – time of the course X is Y”, “where(X,Y) – place of the course X is Y”, and “enroll(X,Y) – student X is enrolled in course Y”. For example:
% facts..
when(102,10).
3.1. Define/write a predicate “schedule(S,P,T)” that associates a student to a place and time of class. See the example query and its result.
?- schedule(a,P,T).
P = 102
T = 10 ;
P = 108
T = 12 ;
3.2. Define/write another predicate “usage(P,T)” that gives the usage times of a classroom. See the example query and its result.
?- usage(207,T).
T = 455 ;
T = 456 ;
3.3. Define/write another predicate “conflict(X,Y)” that gives true if X and Y conflicts due to classroom or time.
3.4. Define/write another predicate “meet(X,Y)” that gives true if student X and student Y are present in the same classroom at the same time.
Part 4. Write the following predicates operating on sets.
4.1. Define a Prolog predicate “element(E,S)” that returns true if E is in S.
4.2. Define a Prolog predicate “union(S1,S2,S3)” that returns true if S3 is the union of S1 and S2.
4.3. Define a Prolog predicate “intersect(S1,S2,S3)” that returns true if S3 is the intersection of of S1 and S2.
4.3. Define a Prolog predicate “equivalent(S1,S2)” that returns true if S1 and S2 are equivalent sets.