Experience with mural in formalising Dust-Expert

The mural system was an outcome of a signi cant e ort to develop a support tool for the e ective use of a full formal methods development cycle. Experience with it, however, has been limited to a small number of illustrative examples that have been carried out by those closely associated with its development and implementation. This paper aims to remedy this situation by describing the experience of using mural for specifying Dust-Expert, an expert system for the relief venting of dust explosions in chemical processes. The paper begins by summarising the main requirements for Dust-Expert, and then gives a avour of the VDM speci cation that was formalised using mural. The experience of using mural is described with respect to users' expectations that a formal methods tool should: (i) spot any inconsistencies, (ii) help manage and organise the speci cations and allow one to easily add, access, update and delete speci cations, (iii) help manage and carry out the re nement process,(iv) help manage and organise theories, (v) help manage and carry out proofs. The paper concludes by highlighting the strengths and weaknesses of mural that could be of interest to those developing the next generation of formal methods development tools.