Use of a specification construction and animation tool to teach formal methods

ZAL (Z Animation in LISP) is a package which allows a Z specification to be incrementally designed and validated in an interactive environment built on Common LISP. A Z specification is transformed into an equivalent ZAL program which can be executed in order to demonstrate the functionality of the intended implementation. ZED is a full screen editor and syntax analyser for Z. Using these two tools as an integrated package encourages and facilitates an exploratory approach to formal specification which reflects the way in which many users of Z (particularly beginners) prefer to approach the specification task. The package has also been used to support the teaching of students following courses in discrete mathematics, formal specification and software development