CSE 571
notes for 11.5.03
professor Luis
PROGOL
looking at the familiar problem of grandparents and parents, how would we find
grandparents if we do not have it defined in terms of parents?
--What is Rule learning?
Given a rule such as grandparent_of(bob, elzabeth),
go and look at the background knowledge and find relations of rules with bob and
Elizabeth, such as parnt_of(bob, harry) parent_of(harry, elizabeth).
Learning for inductive logic programming: given background knowledge, a set of
positive examples and a set of negative examples, find a hypothesis such that the
background knowledge and the hypothesis together entail all the positive examples and
none of the negative.
PROGOL learns first order Horn clauses (ansProlog –not)
a major advantage of using ILP instead of another learner such as NN’s, is that the
learned hypothesis can be automatically translated into the following piece of English
text.
Syntax:
:- modeh(1, p (+type, +type))?
:- modeb(1, q(+type, -type))?
:- modeb(1, r(+type, +type))?
means we want to learn a rule that has predicate p as the head, and predicates q and r are
possible candidates for the body of the rule
1 is the recall, which is the number of solutions.
type is the type of the variable (domain)
+ / - enforces the ordering (in prolog), in our case q’s rule would need to come before r’s
rules.
q and r are the possible rules to search for a rule in.
:- modeh (p
:- modeh (m
