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<head><title>help -- help command</title>
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<div><h1>help -- help command</h1>
<div class="single"><h2>Description</h2>
<div>Various ways to get help:<ul><li><tt>help "Macaulay2"</tt> -- displays the base of the online documentation tree.</li>
<li><tt>help X</tt> -- displays the online documentation for <tt>X</tt></li>
<li><tt>help methods X</tt> -- displays help messages about the methods usable with things of type <tt>X</tt></li>
<li><tt>help methods res</tt> -- displays help messages about the methods usable with the function <tt>res</tt></li>
<li><tt>help methods symbol **</tt> -- displays help messages about the methods usable with the operator <tt>**</tt></li>
<li><tt>help methods (res, X)</tt> -- displays help messages about the methods usable with the function <tt>res</tt> and a thing of class <tt>X</tt></li>
<li><tt>help methods (symbol **, X)</tt> -- displays help messages about the methods usable with the operator <tt>**</tt> and a thing of class <tt>X</tt></li>
<li><tt>help methods (X, Y)</tt> -- displays help messages about the methods usable with a thing of class <tt>X</tt> and a thing of class <tt>Y</tt></li>
</ul>
The <tt>help</tt> command is used to display online documentation. Use <a href="_view__Help.html" title="view online doc with a web browser">viewHelp</a> to display the corresponding documentation in your web browser.<table class="examples"><tr><td><pre>i1 : help
--loading the Macaulay2 documentation from /builddir/build/BUILD/Macaulay2-1.3.1-r10737/Macaulay2/packages/Macaulay2Doc/
o1 = initial help
************
Welcome to Macaulay2
Try entering '2+2' at your next input prompt, which begins with i. The
two output prompts begin with o. The first one, with the equal sign,
'=', gives the value computed from your input, and the second one, with
the colon, ':', tells what type of thing the value is.
Type one of these commands to get started reading the documentation:
* copyright -- the copyright
* help "Macaulay2" -- top node of the documentation.
* help "reading the documentation" --
* help "getting started" --
* help "a first Macaulay2 session" --
* help x -- display the documentation for x
* ? f -- display brief documentation for
a function f
* printWidth = 80 -- set print width to 80
characters
* viewHelp -- view documentation in a browser
* viewHelp x -- view documentation on x in
browser
To read the documentation in info form, in case you happen to be running
Macaulay2 in a terminal window, replace "help" by "infoHelp" in any of
the commands above.
o1 : DIV</pre>
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<tr><td><pre>i2 : help ideal
o2 = ideal -- make an ideal
**********************
Ways to use ideal :
===================
* "ideal(List)" -- make an ideal
* ideal(Sequence), see "ideal(List)" -- make an ideal
* "ideal(Matrix)" -- make an ideal
* "ideal(Module)" -- converts a module to an ideal
* "ideal(MonomialIdeal)" -- converts a monomial ideal to an ideal
* ideal(QuotientRing), see "ideal(Ring)" -- returns the defining ideal
* "ideal(Ring)" -- returns the defining ideal
* ideal(Number), see "ideal(RingElement)" -- make an ideal
* "ideal(RingElement)" -- make an ideal
* "ideal(String)" -- make an ideal using classic Macaulay syntax
* "ideal(Variety)" -- returns the defining ideal
o2 : DIV</pre>
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<tr><td><pre>i3 : help (ideal,List)
o3 = ideal(List) -- make an ideal
****************************
Synopsis
========
* Usage: ideal L
* Function: "ideal"
* Inputs:
* L, a list, or a sequence of ring elements
* Outputs:
* an ideal, which is generated by the list or sequence of ring
elements
Description
===========
+--------------------------------------------+
|i1 : R = ZZ/101[w,x,y,z]; |
+--------------------------------------------+
|i2 : ideal{x^2-w*y, x*y-w*z, x*z-y^2} |
| |
| 2 2 |
|o2 = ideal (x - w*y, x*y - w*z, - y + x*z)|
| |
|o2 : Ideal of R |
+--------------------------------------------+
|i3 : ideal(y^2-x*z,x^2*y-z^2,x^3-y*z) |
| |
| 2 2 2 3 |
|o3 = ideal (y - x*z, x y - z , x - y*z) |
| |
|o3 : Ideal of R |
+--------------------------------------------+
|i4 : E = ZZ/2[x,y, SkewCommutative => true];|
+--------------------------------------------+
|i5 : ideal(x^2,x*y) |
| |
|o5 = ideal (0, x*y) |
| |
|o5 : Ideal of E |
+--------------------------------------------+
|i6 : W = QQ[x,dx, WeylAlgebra => {x => dx}];|
+--------------------------------------------+
|i7 : ideal(dx*x+x*dx) |
| |
|o7 = ideal(2x*dx + 1) |
| |
|o7 : Ideal of W |
+--------------------------------------------+
|i8 : I = ideal(12,18) |
| |
|o8 = ideal (12, 18) |
| |
|o8 : Ideal of ZZ |
+--------------------------------------------+
|i9 : mingens I |
| |
|o9 = | 6 | |
| |
| 1 1 |
|o9 : Matrix ZZ <--- ZZ |
+--------------------------------------------+
See also
========
* "Ideal" -- the class of all ideals
* "PolynomialRing" -- the class of all ordered monoid rings
o3 : DIV</pre>
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Some other potential help topics:<ul><li><tt>help "Gröbner bases"</tt></li>
<li><tt>help "multigraded polynomial rings"</tt></li>
</ul>
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<div class="single"><h2>See also</h2>
<ul><li><span><a href="_view__Help.html" title="view online doc with a web browser">viewHelp</a> -- view online doc with a web browser</span></li>
<li><span><a href="_info__Help.html" title="view online doc with info">infoHelp</a> -- view online doc with info</span></li>
<li><span><a href="_apropos_lp__String_rp.html" title="symbols matching a pattern">apropos</a> -- symbols matching a pattern</span></li>
<li><span><a href="_code.html" title="display source code">code</a> -- display source code</span></li>
<li><span><a href="_examples.html" title="list the examples in documentation">examples</a> -- list the examples in documentation</span></li>
<li><span><a href="_reading_spthe_spdocumentation.html" title="">reading the documentation</a></span></li>
</ul>
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<div class="waystouse"><h2>For the programmer</h2>
<p>The object <a href="_help.html" title="help command">help</a> is <span>a <a href="___Command.html">command</a></span>.</p>
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