'DESTA' is the acronym for the Dialogue Evolutionary Synthesizer of Turnkey Algorithms by means of a natural language (Russian or English) functional specification of algorithms or software being developed. DESTA represents the computer-aided and/or automatic artificial intelligence 'forgiving' system which provides users with software tools support for algorithm and/or structured program development. The DESTA system is intended to provide support for the higher levels and earlier stages of engineering design of software in contrast to conventional Computer Aided Design (CAD) systems which provide low level tools for use at a stage when the major planning and structuring decisions have already been taken. DESTA is a knowledge-intensive system. The main features of the knowledge are procedures, functions, modules, operating system commands, batch files, their natural language specifications, and their interlinks. The specific domain for the DESTA system is a high level programming language like Turbo Pascal 6.0. The DESTA system is operational and runs on an IBM PC computer

Lovitsky, Vladimir A.

Pearce, Patricia D.

English

NASA Technical Reports Server

Lovltsky
N93-17519
Automating Software Design System
DESTA
Vl_d/m/r A. Lo v/tsk y
AssociateProfessor
Software Engineering Department
Instituteof Radioelectronics
Kharkov,Ukraine
(0572)409 II3 (Fax)
Palr/c/aD.Pearce
Professor,Head of Computing Department
Universityof Plymouth
Drake Circus,Plymouth
Devon,PL4 8AA, UK
pat@uk.ac.psw.cd
(0752) 232 541 (Office)
(0752) 232 540 (Fax)
Abstract
"DESTA" " Is the acronym for the _alogue Evolutionary._/ntheslzerof
_/OrnkeyAlgorithms by means of a naturallanguage(Russianor English)functional
specificationofalgorithmsorsoftware beingdeveloped.
DESTA represents the computer-aided and/or automatic artificial
intelligence"forgiving"system which providesusers with software toolssupport
foralgorithmand/or structuredprogram development.
The DESTA system Is intendedto providesupportforthe higherlevelsand
earlierstagesof engineeringdesignof software in contrastto conventionalCAD
systems which providelow leveltoolsforuse at a stagewhen the major planning
and structuringdecisionshave alreadybeen taken.
DESTA Is a knowledge-intenslvesystem. The main features of the
know ledgeare procedures,functions,modules, operatingsystem commands, batch
files,theirnaturallanguagespecificationsand theirinterl/hks.
The specificdomain for the DESTA system is a high levelprogramming
languages likesTurbo Pascal6.0.
The DESTA system isoperationaland runson a IBM PC computer.
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https://ntrs.nasa.gov/search.jsp?R=19930008330 2020-03-17T09:22:15+00:00Z
Lovitsky
I. Introduction
At present software development is the biggest obstacle to major new
breakthroughs in computing. The biggest limitation in software development is the
failure of imagination that people tend to project: '_4user only really knows what
he wants when he sees a f/n/shedattempt'_
How we develop software at present. We tend to develop software in the
same way we did it in the 1960s i.e. it's one instruction after the other. We really
haven't yet got to the point where CAD system or CASE-type tools help out very
much. In order to move toward what we call higher levels of software automation
in the future, we are going to be using more standardized systematic-type modules
for developing software systems.
The end aim of automatic programming is a complete system without the
need to write any code. At present you don't see automatic programming, where
you simply say to the computer: 'OK,Ineed a program to do this,and Io and behold,
out itcomes';
This paper describes aspects of applied research related to the development
of an Intelligentsystem DESTA. The idea Is very simple: we must get lots of
differentsoftware from lots of differentplaces that must work together and must
talk to each other and the output of one can be used as input of the other.
Obviously we need to have vast knowledge base for it.The software should be
developed from reusable software components: "software chips*. To do it we
need to consider some general issue:
• Knowledge content, structure, representation, acquisition, and main-
tenance.
• Inference engine.
• Human-computer interaction,natural language interface, integrated
program development environment.
2. Knowledge Base
Software development is an intensely knowledgebased activity. The
functioning or activity of any intelligent system (natural or artificial) can be
reduced to solving a set of suitable problems, 93% of which belong to so-called
"ill-defined" problems whose solution cannot be expressed by formulae or by
means of using classical or modern mathematics. In this case it is more
convenient for the end user to specify their requirement to the computer by means
of natural language (NL).
By an intelligent system we shall understand a system which enables us to
solve intell1_entproblems
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Lovitsky
2 I. IntelligentProblem
Intuitivelyunder the problem T they will understand the four <X,Q,F,Y>, in
which X stands for the finite set of input data and their specification; Q
represents the goal descriptions,and F is the finite sequence (or set) of rules
transforming X intoY.Thus Y is the finiteset of output data.
Proceeding from a given definition It Is easy to single out at least three
classes of problems, which are characterized by the following relations:
X&Q&FI--Y, (I)
X&Q&YI--F, (2)
X & Q I-- F => Y, (3)
"I--" and "=>" stand for "and", "glve" and "Ifnpllcatlon"where symbols "&",
respectively.
IntelligentDroOlems are characterized by relations (2) and (3).
case the problem to define software chips can be represented by:
In this
T = <5p(x),Dt(x),Nm(F),As(F),Sp(F),Cnd(F),Dc(F),Pr(F),Sp(y),Dt(y)>,
where Dt(x) and Dt(y) are the "input"and "output"data,respectively;
Sp(x) and Sp(y) are their "specification",
Nm(F) is the "algorithmname" coincidingwith the problem name Nm(T);
Dc(F) represents the "declarativedescription" of the finite sequence (or
set) of rules called the "algorithm', Having availableDc(F) the system Knows
How to solve the problem T, but itCannot (isnot able to) solve this problem;
Pr(F) is the "program representation" of F called "program" (or
"module"). Having availableonly Pr(F) the system Does Not Know How to solve
the problem T, i.e.it cannot describe declarativelythe course of its solution,but
because the description of Pr(F) Is "intelligible"tothe system It Can Execute
F (i.e.Can Solve the problem);
The description of "functionality"-As(F), the "condition"of itsexecution -
Cnd(F) and Its "specification"-Sp(F) Includingthe language for the description
of F, the method of solving, the required computational resources for its
implementation etc are brought to conformity with every F.
2.2. Content and Structure of KB
The activity of any natural (or artificial)intelligent system is just
connected wlth solving different problems. Hence, knowledge of these systems
must be predisposed to realize such activity In our opinion the KB should
consist of three components:
(I) Knows WHAT,
(2) Knows HOW,
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Lovitsky
(3) CAN DO Something.
According to the traditional approach to knowledge representation, the
knowledge isdivided into "Declarative"and "Procedural"that does not permit one
to realize the main capability of the human mind: "bootstrapping principle'.
One can distribute among the three part of KB the elements of problem
notion:
(I) Knows WHAT: Sp, Dt, Nm, As, Cnd
Here all the declarative components connected with the specification of the
problem being solved are interlinked.
(2) Knows HOW: Dc(F),
(3) CAN DO Something: Pr(F)
At present there can be no doubt that the possibilities of the artificial
intelligence system (AIS) are defined to a large degree by the organization of the
knowledge store. In the general case, under the memory organization one should
understand the regularity of data distribution in memory assuring the storage of
various links between separate elements of information and representing the main
principleof gestaltpsychology,i.e."the Whole Is greater than the sum of the
parts'. In other words, the structure obtained as a result of integration should
contain more information than had been used for its creation. Apparently this
defines the striking ability of a human being for generating and understanding an
endless number of sentences based on the limited experience with a limited
number of sentences.
Moreover, at every moment of time both a man and AIS deals only with
relatively small fragments of the external world. The corresponding structures are
needed to integrate these fragments separated In time into the integral picture.
All kinds of binary relations can be divided into just four classes: "one-
to-one. "one-to-many. "many-to-one" and "many-to-many" For im-
plementation of these classes of binary relations the four types of elements
corresponding to them are suggested: I-elements, _-elements, Y-elements
and X-elements. Different combination of these elements determine the
different attributes of the structures. The KB of DESTA-system are provided by
the interaction of the different structures as follows:
- L-tree-structure (combination of I- and ,ll,-elements). This is an
initial structure which provides the recognition of new words, the normalization
of well-known words and the determination of direct links with the corresponding
nodes of Sm-structure, Md-structure and Set-structure.
- TB-structure (combination of I-, Y- and _l.-elements). Provides the
understanding of new words.
- Sin-structure (combination of I-, Y-, _- and X-elements). Provides
the handling of new or well-known sentences or sequences of words.
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Lovitsky
- Md-structure (combination of I-, Y- and ,l-elements). Provides the
mapping of the In-, Out-parameters and Cnd(F) interaction for different
modules and algorithms.
- Set-structure (combination of I-, ,t,- and Y-elements). Usually each
module is associated with several other modules logically including it or included
by it. This structure permits the system to map such links.
- PrRl-structure (combination of I-and _-elements). Provides the
storing of production rules and direct access to them.
3. Inference Engine
In the past AIS development was based on the Log/ca/Parad/gm, the main
idea of which was to extract the problem solving from some theorem proof using,
for example, first order predicate calculus (or Horn clause logic which is the
restrictionform of firstorder predicate calculus).
At present itis understandable that the KB of the real AIS Is incomplete,
inconslstentand shouldbe open. In such a case it would be natural to devote
more attention to the human inference process which is based on "plausible
reasoning" using maximum "argumentation" about problem solving within the
framework of KB.
One can single out at least three relativelyindependent mechanisms serving
the "n#t¢ralinference" source:
- integration of Information;
- additlon of informatlon;
- cognitive transformations.
The idea of the _tr_cturedapproach for natural inference is considered.
4. Natural Language Interface
The natural language (NL) was chosen as:
• an external language for knowledge descriptions;
• an/nternal language for knowledge representation;
• a specification language of the problem being solved and non-procedural
or procedural algorithm;
• a communication language between the end users and DESTA system.
Any NL-text handling is performed as follows:
• Any NL-sentence is divided into so-called "nuclear" (the simplest)
sentences. By nuclear sentence (NS) is meant:
- a simple or a simple extended sentence with the direct order of words,
where the subject group can be expressed only by a noun.
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Lovitsky
- a simple or a simple extended sentence with the direct order of words,
where the subject group is expressed by a verb in the form of the imperative mood.
• Any NS is transformed into a form of the NL-statement. The verb of
any NS is just a name of active or state statement. Active NS looks like a
module description (e.g. Remove(what, from, to)) and state NS - as a specifier
(e.g. Be(what, where)_. Every NL-statement consists of the operation name plus
respective parameters determined by the valence of this operation or its
management model or its role frames.
NL-statements represents A-statements, S-statements or R-
statements. A-statement is the statement of action or the active NL-
statement. S-statement is a state NL-statement or a statement of relations
with a subject of inactive state. R-statement represents some relations like
syno-nym, antonym, apart of and so on (e.g."Deletea cursor is a synonym to erase
a cursor", "Ascending sort algorithm as opposed to descending sort algorithm,
"TB-structure isa part of DESTA knowledge base "]
There is a semantic equalitybetween the initialsentence and the finiteset
of NL-statements.
• The finiteset of NL-statements for InltialNL-sentence is represented as
a "concept:
5. Conclusion
At present DESTA is software implemented to proof the correctness of a
paradigm being suggested. In short the keystone of this paradigm is as follows:
• For the end user It is more convenient to specify their requirement to the
computer by means of natural language.
• The system has to automatically yield a readily comprehensible good
structured rapid prototype which /;_ all stages of structured growth should be
executable.
• • Software development Is an Intensely knowledgebased activity.
Using NL-specification we can include in the KB functional descriptions of
"software chips" (SC): modules, procedures, functions,batch files,operating
system commands and algorithms. The SC can be implemented on any program-
ming languages: module-oriented, object-oriented and/or active declarative
languages.The NL-specifications allow us to Jointhem in whole software systems
(we are not discussing here about compatibility SC for different programming
languages).
• Using NL-specification DESTA either extracts from the KB the suitable
SC in accordance with the NL-specification or asks the user for a more detailed
description of the problem being solved.
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Automating software design system DESTA

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