High Quality Content by WIKIPEDIA articles! HYPO is a computer program that models reasoning with cases and hypotheticals in the legal domain. It is the first of its kind and the most sophisticated of the case-based legal reasoners, which was designed by Ashley for his Ph.D dissertation in 1987 at the University of Massachusetts Amherst under the supervision of Rissland. HYPO’s design represents a hybrid generalization/comparative evaluation method appropriate for a domain with a weak analytical theory and applies to tasks that rarely involve just one right answer. The domain covers US trade secret law, and is substantially a "common law" domain. Since the Anglo-American law is operated under the doctrine of precedent, the definitive way of interpreting problems is of necessity and case-based. Thus, HYPO did not involve the analysis of a Statute, as required by the PROLOG program. Rissland and Ashley (1987) envisioned HYPO as employing the key tasks performed by lawyers when analyzing case law for precedence to generate arguments for the prosecution or the defence.