Validating network protocols using a flexible verifier

As a means of developing high reliability communication systems, the combined use of formal description techniques (such as SDL and LOTOS) and verification techniques is desirable. The paper gives a flexible, user-friendly verifier Vega which is based on a model-theoretic methodology that supports verification of temporal properties (e.g., cause-and-effect relationships) expressed in temporal logic for protocol specifications described in LOTOS. Vega is provided with an effective interface function, as well as the function of simple model checking, to give some degree of flexibility for the expression of temporal properties to be verified. Specifically, it allows the user to define useful expressions by combining built-in temporal logic formulas and enter them for use at any time.