@book{SWP-94-04,
year={1994},
author={Claus-Peter Wirth\protect\index{Wirth, Claus-Peter}
    and Lunde, R{\"udiger}},
title={Writing Positive/Negative-Conditional Equations Conveniently},
publisher={{SEKI Publications}},
series={{SEKI-Working-Paper SWP--94--04 (ISSN 1860--5931)}},
address={Univ.\ Kaiserslautern},
note={\url{http://www.ags.uni-sb.de/~cp/p/swp9404}},
abstract={We present a convenient notation for positive/negative-conditional
equations. The idea is to merge rules specifying the 
same function by using case-, if-, match-, and let-expressions. 
Based on the presented macro-rule-construct,
positive/negative-conditional 
equational specifications can be written on a higher level.
A rewrite system translates the macro-rule--constructs into 
positive/negative-conditional
equations.},
}