Greetings from Universal Technical Systems
===============================================

We are pleased to offer you a free copy of the essential part of our
new product, TK Solver Plus. For terms under which this offer is

What is TK Solver and what is in this package?
How to start using this package
What more is available in TK Solver Plus?

W h a t i s T K S o l v e r ?
-----------------------------------

TK Solver Plus is our latest addition to the line of personal
computer software products started with Software Arts's TK!Solver
four years ago. The original TK!Solver won wide acclaim among
engineers, scientists, financial analysts, teachers and students for
cutting short the problem-solving process. TK users have realized
time savings by a factor of 10 to 100, thanks to the fact that TK
accepts equations or mathematical models in their natural form and
generates their solutions regardless of the selection of known
variables, the order of equations, or the location of unknowns on the
left or right side of the equal sign.

TK Plus goes far beyond the original TK. It provides the user with a
comprehensive, open-ended and friendly problem-solving environment.
This free PrevieWare edition of TK Solver (called FREETK) includes
its most unique and powerful parts, the Direct and Iterative Solvers.
It will give you a taste of declarative or rule-based programming as
applied to numerical computations and logical relationships.

While FREETK presents only a part of TK Plus capabilities, it is much
more than an ordinary demo. It will let you solve countless practical
problems within minutes of putting your hands on it. For instance,
it will let you analyze many aspects of loan management after
entering a single formula:

payment = loan * rate / (1 - (1+rate)^-term)

You will be able to describe what's going on in a DC circuit, and
solve for any unknown components after entering

R = R1 + R2 + R3 + ... for a serial connection,

1/R = 1/R1 + 1/R2 + 1/R3 + ... for a parallel connection,

and Ohm's or Kirchhoff's laws in their general form. For AC
calculations FREETK handles complex variables in orthogonal and polar
or exponential notation. Have you ever before heard of just typing
(z,jz) = (x,jx) * (y,jy) and getting solutions for any combination of
two unknowns and four knowns?

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Mathematically speaking, TK will solve any equation or set of
equations, linear or nonlinear. Computationally speaking, you will
be using a higher than "high level" language. You will let the
computer find its way through the maze of mathematical and logical
relationships and, in fact, automatically generate a program each
time you use a TK model for solving a particular problem. And there
is another dimension to TK: It has achieved a proven record as a
shell for developing knowledge bases (consisting of formulas,
mathematical models, empirical data, etc.) and problem solving tools.

How to get started with FREETK
------------------------------

FREETK runs on IBM PC/XT/AT or compatible computers with minimum 192K
RAM and one floppy disk drive, although we suggest that you copy it
to and run it from a hard disk, if available. FREETK doesn't
require, but takes advantage of math co-processor if one is
installed.

Look at the the sample configuration file EXAMPLE.CFG. You may not
need any configuration file if you are satisfied with the default
settings indicated as "Yes". You may use your favorite text editor
to change any "Yes" to "No" as desired, then rename EXAMPLE.CFG to
FREETK.CFG and have it available when you load the FREETK program.

Make sure that the FREETK.HLP and, if needed, FREETK.CFG files are
available from current directory.

The best bet for TK novices is to follow a hard copy of TUTORIAL.TXT.
If you are serious about exploring the TK world you also should make
and keep handy a hard copy of REFCARD.TXT, the file containing an
abridged reference card from TK Solver Plus.

The TK command structure is fairly simple, considering the power and
versatility of the program. The most frequently used top level
commands are displayed at the bottom of the screen (you can have this
prompt removed by changing an appropriate setting in the CFG file to
"No").

The so-called slash commands beginning with / and sheet selection
command beginning with = are supported by option menus. To move
around the TK sheets you can use the standard arrow and special keys
in an intuitive fashion.

FREETK comes with a context-sensitive help in the file FREETK.HLP,
which is a subset of the Help file from full TKSolver Plus with a few
tutorial additions. You should be able to learn from the Help
everything you need to start operating FREETK -- just invoke it by
pressing F1, go to the Help Index, look at and read the major topics
at the beginning, and browse through the rest. Help is there to
serve you at any time you need it. If it is invoked while a TK
session is in progress, it will bring up information relevant to the
current position of the cursor, the current error condition, or
available command options.

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Operating FREETK and taking full advantage of the TK concept take
some amount of know-how and getting-used-to. Here are a few hints:

Everything between TK and the user happens in so-called information
sheets which are displayed in one or two windows on the screen. The
most important ones are the RULE SHEET used for entering and
displaying the rules or equations, and the VARIABLE SHEET where TK
displays the variables with their input values (entered by the user)
and output values or results (generated by TK). You will quickly get
used to this multi-sheet interface, and will appreciate the fact
that certain kinds of information may always be found at certain
places, managed in a consistent and uniform way.

Pressing the function key F2 terminates any command sequence or text
entry in a field, restoring the original contents of the field. When
the cursor is in a Status Field in the Rule Sheet, pressing C works
as a toggle switch bringing a particular rule into and out of
operation -- handy when developing a model and sorting out which
rules affect what.

This leads to another point to keep in mind and take advantage of: in
TK the solution of a model is not a one-way street. It propagates
through the maze of rules, equations and constraints in any
conceivable way. TK excels at inversion or turning the expressions
inside out when evaluating a particular variable. You may want to
help it by, say, writing 1/(1+1/a) instead of a/(1+a) or writing

What more is available in TK Solver Plus ?
-------------------------------------------

By allowing the unbounded use of the Direct and Iterative solvers
with up to 16 lines on the Rule Sheet and 32 lines on each of the
Variable and Unit Sheets, FREETK has a considerable amount of power
in its own right. Nonetheless, FREETK provides only a glimpse of the
full power of TK Solver Plus. Aside from having no restrictions on
the number of lines in any sheet (except those imposed by the amount
of available memory), TK Solver Plus has many features beyond those
available in FREETK.

TK Solver Plus will help you with solving most (if not all) of your
computational/mathematical problems by blending the solvers with more
common concepts such as: arrays of data or lists; high resolution
graphics; spreadsheet-like tabular interface; and procedural
programming. The result is an integrated problem-solving environment
with tools for solving differential equations, nonlinear curve
fitting, arbitrary length integer arithmetic, optimization
techniques, and much more at your fingertips.

L i s t s
~~~~~~~~~
Lists of values may be used to create graphs or tables, and may also
be used to represent rows or columns of matrices. You can think of

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lists as one-dimensional arrays. TK finds a solution for the first
elements in the lists, then the second elements, and so on. F10,
which is not functional in FREETK, is used to initiate a List Solve.

F u n c t i o n s
~~~~~~~~~~~~~~~~~
TK Solver Plus has three kinds of user-definable functions: List
Functions, Rule Functions and Procedure Functions.

LIST FUNCTIONS are useful when the relationships between function
values and arguments can be defined by two interrelated lists of
values. There are four types of mapping of function values and
arguments available: table lookup, step mapping, linear interpolation
and cubic interpolation.

RULE FUNCTIONS are groups of rules which are called or referenced
from the Rule Sheet and may, in turn, call or reference other Rule
Functions and Procedure Functions. Rule Functions simplify the Rule
Sheet and enhance the clarity of long and complex models.

PROCEDURE FUNCTIONS complement TK's approach to problem solving. TK
is a very high-level "declarative" language: once the rules and
constraints are declared, TK uses its powerful built-in algorithms to
generate solutions for given problems. The user-definable Procedure
Functions come in handy when the built-in procedures cannot handle
specific procedural tasks, such as finding the greatest common
denominator of two whole numbers, numerical integration, or using an
iteration technique different from the Newton-Raphson method. TK
Solver Plus comes with a library of Procedure Functions for numerical
analysis, statistical computations, etc.

Procedure Functions consist of a sequence of assignment and control
statements which are executed unidirectionally -- essentially like
programs written in conventional "procedural" languages such as
FORTRAN, Pascal or BASIC. Procedure functions may call or reference
other Procedure Functions or Rule Functions. Recursion is allowed,
i.e., a Procedure Function can call or reference itself.

G r a p h i c s
~~~~~~~~~~~~~~~
Line Charts, Bar Charts and Pie Charts are available in CGA, EGA and
Hercules graphics modes. Pressing F7 (not functional in FREETK) is
all that is required to display a plot.

T a b l e s
~~~~~~~~~~~
Values in lists may be displayed in tabular form simply by pressing
F8 (not functional in FREETK). Tables can also be used in
interactive mode, meaning that changes in values of list elements may
be made and a new solution found without leaving the tabular
display. Interactive tables effectively combine all the mathematical
problem-solving power of TK Solver Plus with the convenience of a

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Numeric Formatting
~~~~~~~~~~~~~~~~~~
TK Solver Plus offers virtually complete control over the formatting
formatting may be found in REFCARD.TXT in a section dealing with the
Numeric Format Sheet and subsheets.

Interface with other programs
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
TK Solver Plus will read and write files in WKS (Lotus 1-2-3), ASCII
and DIF (Data Interchange Format) formats.

---------------------------------------------

TK Solver is available from Universal Technical Systems, Inc. (UTS).
Various versions run on the IBM PC/XT/AT and compatibles, Apple
Macintosh, Apple IIe, DEC Rainbow, DEC PC350, Wang PC, and a variety
of MS DOS machines (Texas Instruments Professional, Data General One,
Canon, Toshiba, Zenith PC and others).

For \$25.00 we will send you a FREETK Follow-up Package including:
- "The TK!Solver Book" co-authored by the originator of the TK
concept, Dr. Milos Konopasek,
- a diskette with 100 TK models for your FREETK, covering a wide
variety of applications, and
- detailed information about TK Solver Plus.

Universal Technical Systems, Inc.
1220 Rock Street
Rockford, Illinois 61101

1-800-435-7887 (outside Illinois)
1-815-963-2220 in Illinois and International

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