Artificial Intelligence and Soft Computing: Behavioral ... - Arteimi.info

ased on the first two data: Offers (market, rebate, Monday-evening), Has-
Official-meeting (Husband, next-Monday-evening). When the third data:
Meeting-shifted (from, next-Monday-evening) is added to the reasoning
system, it starts backtracking and finally changes the status of node n5 (fig.
7.3) from IN-node to OUT-node. The TMS thus always maintains consistency
among the inferences derived by the inference engine.
7.7 Default Reasoning
Reiter’s default logic [11] is an alternative form of non-monotonic logic,
which includes a few First Order statements along with one or more default
assumptions. Formally, let Del be a set of statements, including a set of
axioms W and a set of Default statements D, i.e.,
Del = {D, W}
where the elements of D are of the form:
P: Q1, Q2,...,Qn
R
which may be read as: Given P is true, as long as Q1 through Qn are
consistent with P, one may infer that R holds. Further, when P is absent from
the above statement, i.e.,
: Q1, Q2, ...,Qn
R
it means that as long as Q1 through Qn are consistent with known beliefs, it
may be inferred that R holds.
Another special case of a Default statement is of the form
P:
___________
R
which means that “ if P is true, one may infer that R is true”. The last
statement is different from P → R, which means “if P is true then R is true”,
i.e, when P holds R must hold. But in the previous case “when P holds, R