http://www.ccs.neu.edu/research/demeter/papers/derived-edges/derived-edges.pdf

@TECHREPORT{greg:derived-edges,
AUTHOR = "Greg Sullivan and Karl Lieberherr",
TITLE = "An Object-oriented Design Methodology",
INSTITUTION = "Northeastern University",
YEAR = 1995,
MONTH = "January",
NUMBER = "NU-CCS-95-1",
NOTE = "Was completed in December 1992"
}

There is an interesting connection between relationship aspects
and derived edges. First, at the example level both papers
use a shortest path problem in a network of tracks or roads. 

Higher level correspondences are:

derived edges			relationship aspects
----------------------------------------------------

edge (relation) specified by	relation specified by
  traversal subschema             aspect

relation edges			relationship
specializations:                several specializations:
  functions                       unidirectional
  repetitions
  alternations

relation interface
add				add
match                           to, from
matchall

========
In both cases relationships are specified separately from the classes.
In both cases actual implementation strategies for the relations may be
deferred.

Derived edges compose relations by using traversal schemas
that are evaluated using an evaluation by preparedness approach.