Proposed shorter text for 3.7.2 Composition of Assertions

["Stephen Green" <stephen.green@documentengineeringservices.com>]

With examples modified/removed:

"  3.7.2 Composition of Assertions

There are three dimensions that describe how assertions from a
referenced specification may be included within an umbrella
specification:
 'scope of inclusions',
 'conditionality of inclusions',
 'modification of inclusions'.
These relationships between specifications can be expressed using a
test assertion. This form of a test assertion is a specific form of an
assertion, as it expresses some form of conformance, like a
conformance clause.
Multiple dimensions can be expressed within these relationships, for
example, a subset of test assertions from a reference spec may be
conditionally included in an umbrella specification.


     Scope of Inclusions

An umbrella specification usually relates to a referenced
specification by assuming or requiring conformance of its
implementation to this specification. These conformance requirements
can be expressed in a test assertion's prerequisite or predicates.
The scope of this conformance may be determined by the expressions in
these prerequisites or predicates.
The logical expressions used in the predicate may also include a
conformance requirement for varying scopes of the (current) umbrella
specification as follows:

 conformance to an (entire) umbrella specification
 conformance to a profile of the umbrella specification
 conformance to a specific normative statement from the umbrella specification

Similarly, the logical expressions used in a prerequisite may also
include a conformance requirement for varying scopes of the external
specification as follows:

 conformance to an (entire) referenced specification
 conformance to a profile of an referenced specification
 conformance to a specific test assertion from an referenced specification

Take, for example, a case where a target in an umbrella specification
is conformant to some subset of assertions in a referenced
specification. Subsets of a specification are described as
'Conformance Profiles', and may be expressed via grouping constructs
(using 'lists'):

TA List id: WMSB001
List Description: 'smaller box' assertions of the WidgetMobile Small
Box Specification 1.2
List Members:  TA001, TA002, ..., TA008


TA id: widget-TA109-1
Normative Source: [interpretation of conformance clause to WidgetSpec
1.0] "All widgets conformant to the WidgetSpec 1.0 specification must
also be conformant to the 'smaller box' assertions of the WidgetMobile
Small Box Specification 1.2"
Target: Widget
Predicate: List: WMSB001
Prescription Level: mandatory


    Conditionality of Inclusions

This dimension of inclusion describes the condition of whether
assertions in an umbrella specification  are conformant to a
referenced specification. The prerequisite of the assertion may:
    a. require that optional portions of the referenced specification
be implemented in the umbrella,
    b. conditionally require optional portions of the referenced
specification be implemented in the umbrella (for example, based on
the presence of hardware or some other such support), or
    c. make remaining (required) portions of the referenced
specification optional.


    Modification of Inclusions

This dimension of inclusion describes where an umbrella specification
is conformant to a referenced specification, where some subset of
assertions must be modified. This means of inclusion assumes some
partitioning of the unchanged assertions and modified assertions. You
can use "lists of assertions" to describe in the prerequisite the
subset of assertions that the umbrella specification is conformant to
"unchanged".  The remaining test assertions (the changed set) can be
individually specified as test assertions of the umbrella
specification.
Typically, assertions are modified in a referenced specification that
can  be strengthened in a few ways:

 strengthening the prescription level of an assertion (eg. x MAY do y
=> x MUST do y), or
 strengthening the meaning of an assertion with additional
requirements (eg. IF x THEN z => IF (x AND y) THEN z)."




-- 
Stephen D. Green

Document Engineering Services Ltd



http://www.biblegateway.com/passage/?search=matthew+22:37 .. and voice