Guided Search Technique for LOTOS

Data Types (ADTs) are used to specify the intended effect of concrete data types by defining their properties as a set of data objects with their manipulating operations. Because of their formal base, the ADT specifications can serve as abstract, correct, and unambiguous references for the implementation. LOTOS, as an abstract specification language, uses an ADT based on ACT ONE formalism to define its data types [40]. An ADT in ACT ONE consists of a signature and a set of equations. The signature gives all the syntactic knowledge of a type. It consists of: Chapter 2 Literature Review 14 aSorts: names of data carriers. A sort corresponds to the concept of type in most programming languages (e.g. Pascal). bOperations: functions where each has a domain and a range op: s1,s2,...,sn→ sr where op is the operator name, s1,s2,...,sn are the sorts of the operation's arguments, and sr is the sort of its result. An infix operation can be declared as