In The Name Of Allah Lab 03 1Tahani Aldweesh

objectives Searching for the solution’s. Declaration. Query. Comments. Prolog Concepts. Unification. Disjunction. Conjunction. 2Tahani Aldweesh

Searching for the solution’s Consider the query : is there a person who likes both reading and swimming? 3Tahani Aldweesh

cont Likes(Person, reading) likes(Person, Swimming). The solution are found through searching, matching and backtracking. 4Tahani Aldweesh

Declaration in visual prolog Predicate and their argument must be declared. They are declared in predicate section. Clauses for the predicate are given in clauses section. Dynamic facts can be given in the facts section. Execution starts in the Goal section. 5Tahani Aldweesh

Query: true / false In natural language we ask you : Does Bill Like Cindy? In prolog syntax, we ask prolog : Likes(bill, cindy). Given this query, prolog would answer : Yes. 6Tahani Aldweesh

Queries : getting answers We could ask you in natural language : What does bill like ? In prolog syntax, we ask prolog : Likes ( bill, What). Prolog will return : What=cindy What=dog 2 Solutions 7Tahani Aldweesh

Examples 8Tahani Aldweesh

Using Underscore as a variable The anonymous can be used in place of any other variable. The difference is that the anonymous variable will never get set to value : GOAL Parent(Parent, _ ). But it can also be used in facts! owns(_, shoes). GOAL owns(bill,shoes). GOAL owns(gane,shoes). 9Tahani Aldweesh

Comments 10Tahani Aldweesh

Prolog Concepts Unification : passing parameter,dealing with assignment, Case selection,etc. Search principle: Searching for success (or failure). Top-down, right to left. Backtracking : Providing multiple solutions. Non-determisme, determinism and cut. Recursion. 11Tahani Aldweesh

Unification Unification is performed when a goal or sub-goal Is matched against a suitable fact or left hand side of rule. Unification is made between : The 1 st parameter in the goal (sub-goal). And 1 st parameter in fact/rule-head. “=“ means Unification. 12Tahani Aldweesh

Unification and matching Identical values match each other: Parent(joe,tammy)matches parent(joe,tammy). A free variable can match with any value: Parent(joe, X)matches parent(joe,tammy). A bound variable matched only with it is bound to : X=tammy, Parent(joe,X)matches parent(joe,tammy). Two free variable s unifies each other: Parent(joe,X)matches parent(joe,Y). 13Tahani Aldweesh

Unification Examples 14Tahani Aldweesh

Unification and calculation Visual Prolog support the most know used mathematical functions. They can be tried out by : Unifying a free variable with various calculation,for example: GOAL X=sqrt(4)*7+1 Visual Prolog support logical expressions like: GOAL not(2<=4). 15Tahani Aldweesh

Disjunction “or” – “;” 16Tahani Aldweesh

Conjunction “and” – “,” 17Tahani Aldweesh

Steps for create new project 1)- Open prolog program. 2)- project  new Tahani Aldweesh18

Tahani Aldweesh19 3)- Build  Build. 4)- Build  Execute. 5)- Look at the project tree a file is created named “same name your proj.pro”, double click on it and put your code.

Tahani Aldweesh20 Double click Class Facts Class Predicates Run Statement

Application in this lecture Tahani Aldweesh21

Execute the program Tahani Aldweesh22

Any Question 23Tahani Aldweesh

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