Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages


home | help
ARIBAS(1)		    General Commands Manual		     ARIBAS(1)

       aribas -	Multiprecision Arithmetic Interpreter

       aribas [options]	[<ari-file> [<arg1> <arg2> ...]]

       This man	page was written for Debian since the orginal software did not
       contain a man page.

       Aribas is an interactive	interpreter suitable for  big  integer	arith-
       metic  and  multiprecision  floating point arithmetic.  It has a	syntax
       similar to Pascal or Modula-2, but contains also	 features  from	 other
       programming languages like C, Lisp, Oberon.

       The  simplest  way  to  use aribas is as	a calculator for (big integer)
       arithmetic. After aribas	is started, it displays	a prompt  ==>  and  is
       ready  to  accept input.	Simply enter the expression you	want to	calcu-
       late, followed by a full	stop, and then press RETURN, for example

	   ==> 123 + 456*789.

       Aribas answers

	   -: 359907

       The symbol -: introduces	the result.
       IMPORTANT.  To mark the end of your input, you must always type a  full
       stop `.'	 and then press	RETURN.

       You can assign the result of a calculation to a variable, as in

	   ==> F6 := 2**64 + 1.
	   -: 18446_74407_37095_51617

       This  calculates	 the 6th Fermat	number (** denotes exponentiation) and
       assigns it to the variable F6 (note that	aribas is case	sensitive,  so
       this is not the same as f6).  Later you can use this variable for exam-
       ple in the expression

	   ==> 123**(F6	- 1) mod F6.
	   -: 688_66214_58712_63971

       which shows (by Fermat's	theorem) that F6 is not	a prime	number.
       The three most recent results are stored	in the pseudo variables	_, __,
       and ___.	For example you	can store the last result in the variable x by
       the command

	   ==> x := _.
	   -: 688_66214_58712_63971

       As you can see in the above examples, aribas uses the underscore	 _  to
       structure  the output of	big integers (>= 2**32). Also for input	of in-
       tegers you may use the underscore, the only condition is	 that  immedi-
       ately before and	after the underscore there are digits, example:

	   ==> z := 123_4567_890.
	   -: 1234567890

       Here the	output contains	no underscore, which shows that	z is less than

       Aribas has several built-in functions for  factorization,  for  example
       rho_factorize, which uses Pollard's rho algorithm.

	   ==> rho_factorize(F6).

	   working ..
	   factor found	after 512 iterations

	   -: 274177

       To find the remaining cofactor, give the	command

	   ==> x := F6 div _.
	   -: 6728_04213_10721

       To  test	 whether  this	factor	is  prime,  Rabin's probabilistic test
       rab_primetest can be applied:

	   ==> rab_primetest(x).
	   -: true

       The function rho_factorize is good for finding small factors (say up to
       10  decimal  digits);  for  more	complicated factorization tasks	a more
       powerful	algorithm like the quadratic sieve qs_factorize	should be used

	   ==> qs_factorize(2**128+1).

       (Depending on the power of your computer, it will take a	few seconds up
       to a few	minutes	to get a prime factor of the 7th Fermat	number.)

   Control structures
       The for loop and	the while loop in aribas have a	syntax as in Modula-2.
       For example, the	following command sequence calculates the factorial of

	   ==> x := 1;
	       for i :=	2 to 100 do
		   x :=	x*i;

       As  you	can  see  in  this  example, the input may extend over several

       The above for loop is equivalent	to the following while loop

	   ==> x := 1; i := 2;
	       while i <= 100 do
		   x :=	x*i;

       The branching construct
       if ...  then ...	 elsif ...  else ...  end
       has also	the same syntax	as in Modula-2.

   Multiprecision floating point arithmetic
       Aribas supports different types of floating point numbers which are in-
       ternally	represented with mantissas of different	bit-length:

	       single_float    32 bits
	       double_float    64 bits
	       long_float     128 bits

       and  several higher precisions up to an implementation dependent	limit,
       typically 1024 or 4096 bits, which can be determined  by	 the  function
       max_floatprec().	By default, when calculating with numbers of data type
       real, single_floats are used. This corresponds to a precision of	 9  to
       10  decimal  places.  A precision of 4096 bits corresponds to over 1200
       decimal places.

       The precision can be changed  using  the	 function  set_floatprec.  The
       function	 takes one integer argument, which is the desired precision in
       bits. It	is automatically rounded to the	next higher  available	value.
       For example, after

	   ==> set_floatprec(100).
	   -: 128

       the floating point precision is 128 bits	and you	can calculate

	   ==> arctan(sqrt(3)).
	   -: 1.04719_75511_96597_74615_42144_61093_16762_8

	   ==> _/pi.
	   -: 0.33333_33333_33333_33333_33333_33333_33333_33

   User	defined	functions
       The  user  can define his or her	own functions. A typical example looks

	   ==> function	fac(n: integer): integer;
		   x,i:	integer;
		   x :=	1;
		   for i := 2 to n do
		       x := x*i;
		   return x;

       If you have entered this	correctly, aribas echoes the function name

	   -: fac

       and from	now on you can use fac in the same way as a built-in function,

	   ==> fac(32).
	   -: 2_63130_83693_36935_30167_21801_21600_00000

       Note  that  inside  function definitions	all used variables must	be ex-
       plicitly	declared, whereas on top level of the aribas interpreter vari-
       ables  can  be  simply created by assignments. Here is another example,
       which shows some	other data types supported by aribas:

	   ==> function	sqrt_list(n: integer): array of	real;
		   vec:	array[n] of real;
		   i: integer;
		   for i := 1 to n do
		       vec[i-1]	:= sqrt(i);
		   return vec;

       This function returns an	array of the square roots of the integers from
       1 to n, for example

	   ==> sqrt_list(10).
	   -: (1.00000000, 1.41421356, 1.73205081, 2.00000000,
	   2.23606798, 2.44948974, 2.64575131, 2.82842712, 3.00000000,

       In  a  bigger  programming project where	you need several functions you
       would not enter them directly at	the  aribas  prompt  but  prepare  the
       function	 definitions  with  an external	text editor and	save them in a
       file  with the extension	.ari , for example abcd.ari .  This  file  can
       then be loaded by aribas	using the command

	   ==> load("abcd").

       If there	is a syntax error in the file, you get an error	message	of the

	   error in line <= 23 of loaded file
	   if: end expected

       which tells you (in this	example) that there is an error	in the if con-
       struct in line 23 or earlier in the file. (Note that the	error messages
       are sometimes not very precise.)	You can	then  correct  the  error  and
       load the	file again.

   Online help
       The command

	   ==> symbols(aribas).

       returns	a  list	 of  all  keywords  and	 names of builtin functions of
       aribas.	This list has about 180	entries, and begins and	ends  as  fol-

       (ARGV,  _,  __,	___, abs, alloc, and, arccos, arcsin, arctan, arctan2,
       aribas,	array,	atof,  atoi,  begin,   binary,	 bit_and,   bit_clear,
       bit_length,  ......  , tolower, toupper,	transcript, true, trunc, type,
       user, var, version, while, write, write_block, write_byte, writeln)

       For most	of the symbols in this list, you can get a short  online  help
       using the function help(). For example, the command

	   ==> help(ARGV).

       gives an	information on the builtin variable ARGV, whereas

	   ==> help(while).

       describes  the  syntax  of the while loop. If you need more information
       than that contained in the online help, consult the documentation which
       can be found in /usr/share/doc/aribas.

   How to exit
       To end an aribas	session, type exit at the aribas prompt

	   ==> exit

       and then	press the RETURN (ENTER) key.

       If you don't want to leave aribas, but want to break out	of an infinite
       loop or a calculation that lasts	too long, type CONTROL-C (if  you  are
       running aribas from within Emacs, you must press	CONTROL-C twice). This
       will (in	most cases) stop the current calculation  and  return  to  the
       aribas prompt.

       When you	are not	using the Emacs	interface but the command line version
       of aribas, you sometimes	get into the following situation: Some	previ-
       ous line	contains a typing error, but you cannot	return to that line to
       correct it.  In this case you should simply type	a full stop `.'	, fol-
       lowed by	RETURN.	You will get an	error message which you	can safely ig-
       nore, and a new prompt ==> appears, allowing you	to try again.

       aribas [options]	[<ari-file> [<arg1> <arg2> ...]]

       The following options are available:

       -q     (quiet mode) Suppresses all messages to the screen (version  no,
	      copyright	notice,	etc.) when aribas is started

       -v     (verbose mode, default) Does not suppress	messages to the	screen
	      when aribas is started.

       -c <cols>
	      aribas does its own line breaking	when writing  to  the  screen.
	      Normally	it  supposes  that  the	screen (or the window in which
	      aribas runs) has 80 columns. With	the -c option you can set  an-
	      other  number, which must	be between 40 and 160 (in decimal rep-
	      resentation).  For example, if you run aribas in an Xterm	window
	      with  72	columns,  use the option -c72 (or -c 72, the space be-
	      tween -c and the number is optional).

       -m <mem>
	      Here <mem> is a number (in decimal  representation)  between  64
	      and  16000.  This	 number	 indicates  how	 many Kilobytes	of RAM
	      aribas should use	for the	aribas heap. The default value depends
	      on  the  options used when aribas	was compiled. Typically, under
	      UNIX or LINUX it is 6 Megabytes, corresponding to	-m6000

       -h <path	of help	file>
	      The online help of aribas	depends	on  a  file  aribas.hlp	 which
	      should  be  situated   in	 the range of the environment variable
	      PATH. If this is not the case you	can specify the	exact path  of
	      the  help	 file  with  the  -h  option.  If for example the file
	      aribas.hlp is in the directory /usr/local/lib, use the option -h
	      /usr/local/lib  (the  space  after -h is not necessary).	The -h
	      option can also be used if the help file has a  different	 name.
	      If  the help file	is named help-aribas and lies in the directory
	      /home/joe/ari, use -h/home/joe/ari/help-aribas.

	      With a properly installed	Debian package of aribas it should not
	      be necessary to use this option.

       -p <ari-search-path>
	      With this	option you can specify a search	path for loading files
	      with aribas source code. <ari-search-path>  may  be  either  the
	      (absolute)  pathname of one directory or several pathnames sepa-
	      rated by colons.	Suppose	that you have called aribas  with  the


	      and that your home directory is /home/alice/. Then the command

		   ==> load("factor").

	      will  search the file factor.ari first in	the current directory,
	      then in  the  directory  /usr/local/lib/aribas  and  finally  in

       -b     Batch mode when loading an aribas	source code file from the com-
	      mand line, see below.

       One letter options which	require	no arguments may be merged, for	 exam-

	   aribas -q -b

       is equivalent to

	   aribas -qb

   Further command line	arguments
	      The  next	command	line argument after the	options	is interpreted
	      as the name of a file with aribas	source code. If	the file  name
	      has  the extension .ari, this extension may be omitted. The file
	      is loaded	as if the command load("_ari-file_")  had  been	 given
	      after  the  start	of aribas at the aribas	prompt.	If the file is
	      not found	in the current directory it is searched	in the	direc-
	      tories  specified	by the -p option.  If the option -b was	given,
	      the file is loaded and executed.	Afterwards aribas exits	 with-
	      out showing it's prompt. If the file cannot be loaded completely
	      because of an error, aribas exits	immediately  after  the	 error

       <arg1> <arg2> ...
	      When  further command line arguments follow _ari-file_, they are
	      collected	(as strings) together with _ari-file_  in  the	vector
	      ARGV  which can be accessed from within aribas.  Example:	If you
	      call aribas with the command line

		   aribas startup 4536 eisenstein

	      and the current directory	contains the  file  startup.ari,  then
	      aribas loads it and the vector ARGV has the form

		  ==> ARGV.
		  -: ("startup", "4536", "eisenstein")

	      If  you  need  some arguments as numbers and not as strings, you
	      can transform them by atoi (or atof); in our example

		  ==> x	:= atoi(ARGV[1]).
		  -: 4536

	      will do it. The length of	the vector ARGV	can be	determined  by

       You  can	 run aribas from within	Emacs by giving	the command (in	Emacs'

	    M-x	run-aribas

       (If you don't have a META key, use ESC x	instead	of  M-x)  Then	aribas
       will be loaded into an Emacs window with	name *aribas* and you can edit
       your input to aribas with the usual Emacs commands.

       If your input ends with a full stop '.' and you	press  RETURN,	it  is
       sent  to	 aribas.   If  however your complete input does	not end	with a
       full stop, (for example in response to a	readln), the input is sent  to
       aribas by C-j (Control-j) or C-c	RETURN.

       If  you want to repeat a	previous input,	M-p (or	ESC p) cycles backward
       through input history, and M-n (or ESC n) cycles	forward.

       A Control-C is sent to aribas by	C-c C-c	(press C-c twice).

       It is also possible to start aribas from	Emacs with command line	 argu-
       ments. For this purpose the command

	    C-u	M-x run-aribas

       has to be given.	Then a prompt

	    run-aribas:	aribas

       appears	in  the	 Minibuffer  of	Emacs and you can complete the command
       line, for example

	    run-aribas:	aribas startup 4536 eisenstein

       (see above).

       Options for running aribas can be specified also	using a	 configuration
       file with name .arirc.  Aribas searches for a configuration file	in the
       following order:

	   1) the current directory
	   2) the home directory of the	user

       There is	a third	possibility: You can define  an	 environment  variable
       ARIRC  containing the name of the configuration file (which may be dif-
       ferent from .arirc), including the full path.

       In the configuration file you can specify all command line options  de-
       scribed	above  which begin with	a - sign, however a separate line must
       be used for every single	option.	Lines beginning	with the  character  #
       or  empty  lines	 are  ignored.	 In  addition to the options described
       above, the configuration	file may contain aribas	source code. For  this
       purpose there must be a line reading


       Then  everything	 after	this line is treated as	aribas source code and
       executed	when aribas is started.

       The existence of	a configuration	file for aribas	does not  exclude  the
       possibility  to	give command line arguments. If	an option (e.g.	the -m
       option) is specified both in the	configuration  file  and  the  command
       line  but  with different values, then the specification	at the command
       line is valid. Analogously, a -v	option on the command line overrides a
       -q  option  in  the  configuration file.	 If there is -init code	in the
       configuration file and an <ari-file> argument at	the command line, then
       the  -init  code	 is  executed  first  and afterwards the <ari-file> is
       loaded and its code executed.

       $ARIRC, .arirc, $HOME/.arirc

	      Optional configuration file.

       $ARIRC Location of the optional configuration file.


       More  information  on   how   to	  use	aribas	 can   be   found   in

       The	aribas	   home	    page     is	    http://www.mathematik.uni-

       Bug reports should be sent by email to

       Otto Forster <> is the	author of  the
       aribas program. This man	page was compiled by Ralf Treinen <treinen@de-> from the aribas  documentation	 for  the  Debian  package  of
       aribas, and supplemented	by the author.

ARIBAS				 February 2001			     ARIBAS(1)


Want to link to this manual page? Use this URL:

home | help