Changes from version 0.99

0:

New version number.

0:

Was "The structure of this document is as follows:".

0:

Version description.

0:

Citation of Note M-4 added.

1:

Clarification.

1.3:

Clarification.

1.3:

Strong equations are derivable from existential ones without using disjunction or negation.

1.4:

Clarification.

2:

Clarification.

2:

Well-formedness of terms is not defined.

2:

Clarification.

2:

Clarification.

2.1.1.1:

S for sorts in concrete syntax examples replaced throughout by s.

2.1.1.1:

Unhelpful explanation removed.

2.1.2.1:

ON for operation names in concrete syntax examples replaced throughout by f.

2.1.2.1:

Clarification.

2.1.2.1:

Clarification.

2.1.2.1:

Clarification.

2.1.2.1:

Clarification.

2.1.2.2:

Clarification.

2.1.3.1:

PN for predicate names in concrete syntax examples replaced throughout by p.

2.1.3.1:

Typo.

2.1.3.2:

Clarification.

2.1.4.1:

A warning about selectors usually being partial has been added.

2.1.4.1:

Further restrictions are imposed on datatype declarations, to avoid pathological examples that would undermine the relationship between free datatype declarations in basic specifications and the corresponding structured specifications.

2.1.4.2:

Constructors in free datatype declarations are injective.

2.1.4.2:

Selectors in free datatypes are as undefined as possible.

2.3.1:

Clarification.

2.3.4.3:

Typo.

2.3.4.3:

The mixfix identifier `__ __' is regarded as an infix.

2.3.4.3:

Clarification.

2.4:

Clarification.

2.4:

Clarification of the distinction between mixfix and ordinary identifiers.

2.4:

Removal of an inconsistency with Appendix C.

2.4:

Clarification.

4.1.2:

Introductory comment added.

4.1.2.1:

Clarification that unions of sorts in free datatype declarations are always disjoint unions.

4.1.2.1:

Free datatypes must not affect the overloading relation of the local environment.

4.2.1:

Well-formedness of terms is not defined.

5:

Clarification.

5:

Implicit views have been eliminated.

5:

Morphisms determined by symbol maps between signatures are as much as possible identity.

6.1.5:

Clarification.

6.2:

Introductory remarks added, and sectioning adjusted.

6.2.1:

Sentence moved to below.

6.2.1:

Sentence moved from above.

6.2.1:

Explanation of the rôle of imports.

6.2.2:

Clarification.

6.2.2:

The imports are added to the local environment for arguments.

6.2.2:

Clarification.

6.2.2:

Correction of " typo.

6.2.2:

Clarification.

6.2.2:

Push-out explained.

6.3:

Introductory remarks changed, and sectioning adjusted.

6.3.1:

A view definition is well-formed only if the signature morphism is uniquely determined.

6.3.1:

Clarification of the scope of parameters in generic view definitions.

6.3.2:

Clarification that views have to provide the required models.

6.3.2:

Clarification that instantiated generic views have to provide the required models.

6.3.2:

Implicit fitting views have been removed.

6.4.1:

QUAL-ID, TYPE introduced, since a:s might be either a constant function or a unary predicate.

6.4.1:

Clarification.

6.4.1:

Symbol lists determine sets of qualified symbols.

6.4.2:

Clarification.

6.4.2:

Symbol maps determine maps between qualified symbols.

6.5:

Subsort embeddings do not extend to compound identifiers.

6.5:

Ensuring semantics gives push-outs when defined.

8:

The concrete syntax of architectural specifications is no longer tentative.

8.1.1:

Clarification of the types of implicit generic functions.

8.1.1:

Explanation of unit specifications extending signatures of imported units.

8.2:

A couple of changes to the abstract syntax of unit specifications, not affecting the way they are written: UNIT-SPEC-NAME is replaced by SPEC-NAME (since they cannot be distinguished context-freely); and an explicit `closed' construct is introduced (cf. closed structured specifications).

8.2:

Implicit closing of defined unit specifications, and no longer any distinction between names of unit specifications and of ordinary specifications.

8.2.3:

An explicit `closed' construct for unit specifications is introduced (cf. closed structured specifications).

8.3:

Clarification.

8.3.1:

Sharing is related to the overloading relation.

8.3.1.1:

Renaming should not introduce new sharing.

8.3.1.5:

Explanation of unit applications made more uniform with that of instantiations.

8.3.1.5:

Each argument should fall into the domain of the generic unit.

9:

Downloaded specifications are not necessarily from the latest version of the remote library.

10:

The concrete syntax of libraries is no longer tentative.

10.2:

A library identifier may be a path of file names.

10.2:

Library identifiers determine library location.

A:

Changes in grammars are indicated by `!' at the left of each changed line.

B:

Changes in grammars are indicated by `!' at the left of each changed line.

C:

The reference to the original concrete syntax document has been removed. Also, the adjective `proposed' is no longer applied to the concrete syntax.

C:

Obsolete citation.

C:

Clarification.

C.2:

Changes in grammars are indicated by `!' at the left of each changed line.

C.3:

Corrected keywords.

C.3:

Disambiguation rules for architectural specifications added.

C.4:

Minor addition to the list of rejected ISO Latin-1 characters.

C.4:

Lexical syntax of URL is distinct from that of PATH.

C.5.2.1:

Label annotations may be allowed more generally in lists.

D.3:

Names are displayed with mixed upper and lower case when `small-caps' are not available.

E:

The introduction and the examples themselves have been revised.

F:

Updated with the progress that has been made since version 0.99 appeared.