This paper illustrates how software can be described precisely using L
D-relations, how these descriptions can be presented in a readable man
ner using tabular notations, and one way such descriptions can be used
to test programs. We describe an algorithm that can be used to genera
te a test oracle from program documentation, and present the results o
f using a tool based on it to help test part of a commercial network m
anagement application. The results demonstrate that these methods can
be effective at detecting errors and greatly increase the speed and ac
curacy of test evaluation when compared with manual evaluation. Such o
racles can be used for unit testing, in situ testing, constructing sel
f-checking software, and ensuring consistency between code and documen
tation.