================================================================================ P9409 J.F. Groote & J.J. van Wamel "Algebraic data-types and induction in muCRL" In this paper a thorough treatment of elementary data types is given in the specification language muCRL, which integrates data specification with process specification. Data specification in muCRL is directly based on the theory of algebraic data types, which is an equational theory, extended with a rule for constructor induction. Specifications of the following data types and structures are given: booleans, natural numbers, modulo arithmetic, sets, bags, queues, tables, and `windows'. Moreover many standard functions are specified and useful properties are derived. For most of the data types also alternative induction schemata are derived, and equality functions are provided that identify exactly those terms that are derivably equal.