A Triptych Software Development Paradigm - Correct System Design: Recent Insights and Advances - page 47

how the human analyser can go about performing the analysis \by hand"! Per-
forming an analysis function takes input from a database and delivers output to
a result storage. Administrative operations, not shown, may move data from the
result storage to the database.
6.2 A Second Narrative
Next we reformulate, more systematically, the above symbol explication:
Layers and Levels: Figure 2 displays one layer, with three levels, of a hierar-
chically structured federated and combined geographic information system and
demographic information system: GIS+DIS. (Further layers are referred to im-
plicitly.)
Each of the three large \curtains" (cascaded in the upper left corner of the
gure) diagram a table like structure: Domain Name Table (the D level), Cat-
egory (or rype) Designator Table (the C level), respectively Version Identier
Table (the V level).
Domain Name Tables: One accesses the (or, in general, a) Domain name table
from a root, a sentinel, Hierarchy designator (h).
Each entry in the Domain name table contains a distinct domain name (d:D),
a (reference to explanatory) text (q: Text ), (a reference to) an operations table
(os), and a (reference to a Category designator table (the latter only shown by
an arrow).
One accesses a Category designator table \through" (or via) a Domain name
table entry.
Type Designator Tables: Each Category designator table entry contains a dis-
tinct type designator (c:C), a (reference to explanatory) text (q: Text ), (a ref-
erence to) an Operations table (os), and a (reference to a) Version identier
table.
One accesses a Version identier table through a Category designator table
entry.
Version Identier Tables: Each Version identier table entry contains a distinct
version identier (v:V), a (reference to explanatory) text (q: Text ), (a reference
to) an operations table (os), (a reference to) data, and a (reference to an) [sub-
]hierarchy (h).
Data Access: One accesses Data through a version identier table entry.
Traversing Hierarchy Layers: One also accesses a sub-hierarchy (the \next"
layer) through the H item of a version identier table entry.
Operations Tables: At any D, C or V level one can access an operations table.
Each Operations table (O) entry contains a distinct operations name (on:On), (a
reference to) explanatory text (q: Text ), (a reference to) the type of the operation
designated, and (a reference to) the operation [itself!].