trace {relations} | R Documentation |
Traces of Endorelations
Description
Compute the left or right trace of an endorelation.
Usage
relation_trace(x, which)
Arguments
x |
an endorelation. |
which |
one of |
Details
Let R
be a crisp endorelation. The left and right trace of
R
contain all pairs x, y
for which z R x
implies
z R y
for all z
(left trace) or y R z
implies
x R z
for all z
(right trace), respectively. These are
the largest (in the natural ordering of relations with the same
domain) relations such that R * S \le R
or S * R \le R
,
respectively (where *
denotes composition). In the fuzzy case,
the memberships of the traces can be defined as the infima over the
corresponding fuzzy membership implications. See Chapter 2.3 in Fodor
and Roubens (1994) for more information.
References
J. Fodor and M. Roubens (1994), Fuzzy Preference Modelling and Multicriteria Decision Support. Kluwer Academic Publishers: Dordrecht.