but when we state that A 'equals' B, as well having to know what we mean
by A and B we also have know what we mean by 'equals'. This section
explores the role of observers; how different types of observ- er see
different things as being equal, and how we can produce algo- rithms to
decide on such equalities. It also explores how we go about writing
specifications to which we may compare our SCCS designs. - The final
section is the one which the students like best. Once enough of SCCS is
grasped to decide upon the component parts of a design, the 'turning the
handle' steps of composition and check- ing that the design meets its
specification are both error-prone and tedious. This section introduces
the concurrency work bench, which shoulders most of the burden. How you
use the book is up to you; I'm not even going to suggest path- ways.
Individual readers know what knowledge they seek, and course leaders
know which concepts they are trying to impart and in what order.