Page 224 - DCAP507_SYSTEM_SOFTWARE

System Software

Notes Forward Translation: offers translation of reverse-axis path. Limited to 8 types of reverse-axis
path listed in documentation.
Canonic Forward Translation: offers translation of reverse-axis path rewriting into canonic
form. Supports path with multiple axes.
Enhanced Canonic Forward Translation: enhancement of canonic forward translation algorithm.
More optimized query with reduction in joins, loops and document accesses.

Self Assessment

Fill in the blanks:
13. ………………….. is used to specify the general and value comparison operator through its
condition attribute.
14. The main window presents the toolbar, drawing panel and …………………. .

14.5 Canonic Systems and Formal Systems

A formal system is like a game in which tokens are manipulated according to rules in order to
see what configurations can be obtained.
For examples: chess, checkers, go, tic-tac-toe. For examples: marbles, billiards, baseball.
All formal games have three essential features:
 They are token manipulation games;
 They are digital; and

 They are finitely playable.
Explanation

1. The tokens ... are just the “pieces” (E.g., markers or counters) with which the game is
played. (E.g., chessmen, go stones, bits, 0s and Xs of tic-tac-toe).
2. Manipulating tokens means one or more of the following:
 relocating them (e.g., moving them around on some board)
 altering them (or replacing them with different ones)
 adding new ones to the position; and/or

 taking some away.
3. A digital system is a set of positive and reliable techniques (methods, devices) for producing
and reidentifying tokens, or configurations of tokens, from some prespecified set of types.
A positive technique is one that can succeed absolutely, totally and without qualification
... has the possibility of succeeding perfectly.
We can substitute “writing” and “reading” for “producing” and “reidentifying”, but only
with two warnings: (1) writing isn't just making pen or pencil marks, but rather any kind
of token manipulation that changes the formal position ... and (2) “reading” implies
nothing about understanding (or even recognition) but only differentiation by type and
position.
4. Finitely playable ... no infinite or magical powers required. A finite player is assumed to
have some finite repertoire of specific primitive operations (e.g., move a chess piece,
write a bit, read a bit) any finite number of times.

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