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I: OPERATOR PRECEDENCE IN AL-JABR
[See Manual Part I (page 3)]
1: (),[],{} <i.e all bracketed expressions and summation or product of sequences are evaluated first of
all>
2: ! <factorial>
3: - <unary minus>
4: sin,cos,tan,tanh,abs,tanh,sinh,cosh,asin,acos,atan,sqrt,log,ln,exp
5: ^
6: *,/,\,div,mod
7: +,- <binary plus and minus>
Whithin any given precedence level the operators are evaluated from left to
right EXCEPT on level 4 where they are evaluated from right to left. For
instance, 16/4*2 will return 8 because since the / and the * are on the
same level, they are considered from left to right and the / is evaluated
first. However sin cos x would first of all evaluate cos x and then find
the sine of that.
II: AL-JABR ERROR MESSAGES
When Al-Jabr meets a difficulty it cannot handle, or if it can't
understand your command, an error message will be issued and you'll
generally have to correct the problem and re-enter the command. Here are
Al-Jabr's error messages and explanations of the situations that might have
caused them.
Error 00: Unrecognized command.
This means Al-Jabr does not understand your command at all. The only
commands, apart from variable assignment, recognized by Al-Jabr at this
time are "store", "show", "print", "plot", "over", "cfit", "capture", and
"quit".
Error 01: Syntax error in command.
Al-Jabr knows your command but you didn't follow the required syntax.
See the manual section on commands (part II) for descriptions of the
correct syntax.
Error 02: Number too large or small to process.
Al-Jabr can only handle numbers between about -1.7e+308 and 1.7e+308
(which is quite an enormous range actually) and if it comes across any
number outside this range in any calculation the above error will occur. If
this error occurs you must take steps to reduce the magnitude of initial,
intermediate or final values in the calculation.
Error 03: The argument to FUNCTION is out of its domain.
Where FUNCTION is replaced by the mathematical function that caused
the error. This means that the argument to the function is out of the
domain in which the function can be evaluated. For example, a negative
argument to the logarithm or square root functions will cause such an
error.
Error 04: The argument to FUNCTION is too large.
Some functions, notably sin, cos, sinh and cosh, are difficult to
evaluate accurately when their arguments are too large. If Al-Jabr cannot
accurately evaluate a function for this reason the above error will be
generated.
Error 05: A number approaching +/- infinity was encountered.
This is similar to error 2 and occurs when Al-Jabr encounters a
singularity.
Error 06: Division by Zero.
A division by zero has been attempted, resulting in a value Al-Jabr
cannot handle.
Error 07: Syntax error in expression.
There is a logical error in your mathematical expression. Quite a few
situations can cause this error. The most common are forgetting to close a
bracket and missing operators. Please check the expression you last used
and make sure it is valid under the rules of Al-Jabr and mathematics.
Error 09: Syntax error in sequence summation of product.
Check that you included all the required parameters, and commas, and
closed the bracket of your sequence summation or product. The correct
syntax for sequence summation and product is explained in part I of the
manual.
Error 10: Undefined user expression.
If you are trying to specify a stored user expression with the #X
notatuion, X must be a digit between 1 and 9 and there must be no space
between the "#" and the digit. In any other case the above error will be
generated.
Error 11: Invalid horizontal axis range.
This occurs in the plot function when either you specify the minimum
and maximum ranges for the horizontal axis to be the same, or if you make
the minimum larger than the maximum.
Error 12: Invalid vertical axis range.
This occurs in the plot function when either you specify the minimum
and maximum ranges for the vertical axis to be the same, or if you make the
minimum larger than the maximum.
Error 13: Invalid statistics file format.
Al-Jabr cannot correctly obtain data from the file you specified with
the "cfit" command. See the "cfit" command description for the correct
format of the data file.
Error 14: Unable to create the file FILENAME.
Most probably FILENAME (which is replaced by whatever filename Al-Jabr
is having trouble with) is not a valid DOS filename.
Error 15: Unable to open data file FILENAME.
The FILENAME you specified cannot be found on the path you specified
(or on the current path if you didn't specify a path) or perhaps it is not
a valid DOS filename.
Error 92, Error 93, Error 99.
These errors are not ever meant to occur, and if they do, they might
reflect serious bugs in Al-Jabr. For this reason if you encounter any of
these errors please contact me immediately and tell me which one you
encountered and the circumstances under which you encountered it. My
Prodigy ID number is KTXR86A; you can send me mail at the following
address:
Uchenna Ogbuji
c/o Dr L. U. Thomas-Ogbuji
20373 Lorrain Road #F-7
Fairview Park OH 44126
or you can leave e-mail for me (Uche G. Ogbuji) on Ed Gelb's Database BBS
[300,1200 baud, 8/1/N] #(201)-694-7425.