LCL type specifications

dear Larch-interested people,
My students are using LCL for a project,
and found very few info in the Larch book
about LCL type specification.
More precisely, we need info about different use of LCL
abstract types:

                - Mutable
                - Immutable
                - Spec

When is better to use one instead of the others ?
We are very interested in having semantics hints and some examples.

                        Thanks in advance for your contribution

Paolo Ciancarini
Univ. of Bologna, Italy

* Prof. Paolo Ciancarini  (cianca@cs.unibo.it)
* tel:     +39 51 354422 fax: +39 51 354490
* Dip. di Matematica - pza. di Porta S.Donato 5, 40127 Bologna - Italy