1. Logic programming

2. Introduction To express program in symbolic logic Also called declarative language Only the specification of desired results are stated State the form of the result rather than how a result is to be computed Logic programming is a declarative approach of writing computer programs based on Logic

3. Brief history 1970s AI group To specifying predicate calculus Prolog

4. Predicate calculus Proposition: a logical statement that is true or not true Formal logic describes proposition that allows them to be checked or validity

5. Logic Programming – Example Suppose we have the following sentences 1. CS student of NTHU must take the core course cs2403 2. A CS student can not obtain a degree without passing the required course I am a CS student of NTHU and want to obtain a degree, should I pass cs2403?

6. /* Filename: ancestor.pro This program creates a small set of facts and rules on who is the ancestor of whom. The user types the desired goal interactively when the program is run.*/ /* ancestor(A, B) means A is an ancestor of B */ ancestor(bob, susan). ancestor(A, X) :- parent(A, X). ancestor(A, X) :- parent(A, C), ancestor(C, X). /* parent(P, C) means P is a parent of C */ parent(fred, sally). parent(tina, sally). parent(sally, diane). parent(sam, bill).

7. Logic Programming – Prolog Query Queries: ancestor(fred, sally). Yes ancestor(fred, diane). Yes ancestor(fred, bill). No

8. Logic Programming – Reference Book: Ralph P. Grimaldi, DISCRETE AND COMBINATORIAL MATHEMATICS, 5TH ED, Pearson Education, 2004 Ulf Nilsson and Jan Ma luszy_nski, LOGIC, PROGRAMMING AND PROLOG, 2ND ED, Ulf Nilsson and Jan Ma luszy_nski, 2000 Web: http://cis.stvincent.edu/carlsond/prolog.html http://ktiml.mff.cuni.cz/~bartak/prolog/index.html http://www.cs.auckland.ac.nz/~j-hamer/07.363/prolog-for-se.html http://www.swi-prolog.org/