Difference between revisions of "ApCoCoA-1:DA.InitialOfDer"

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(Description update.)
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</syntax>
 
</syntax>
 
<description>
 
<description>
DA.InitialOfDer returns the polynomial leading coefficient of polynomial F regarded as polynomial in the derivative X.
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<ref>DA.InitialOfDer</ref> returns the polynomial leading coefficient of polynomial <tt>F</tt> regarded as polynomial in the derivative <tt>X</tt>.
 
<itemize>
 
<itemize>
 
<item>@param <em>F</em> A differential polynomial.</item>
 
<item>@param <em>F</em> A differential polynomial.</item>
 
<item>@param <em>X</em> A indeterminate.</item>
 
<item>@param <em>X</em> A indeterminate.</item>
<item>@return Initial of F wrt. X.</item>
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<item>@return Initial of <tt>F</tt> wrt. <tt>X</tt>.</item>
 
</itemize>
 
</itemize>
 
<example>
 
<example>

Revision as of 12:52, 7 July 2009

DA.InitialOfDer

Computes the initial wrt. a given derivative.

Syntax

DA.InitialOfDer(F:POLY, X:INDET):POLY

Description

DA.InitialOfDer returns the polynomial leading coefficient of polynomial F regarded as polynomial in the derivative X.

  • @param F A differential polynomial.

  • @param X A indeterminate.

  • @return Initial of F wrt. X.

Example

Use QQ[x[1..2,0..20]];
Use QQ[x[1..2,0..20]], Ord(DA.DiffTO(<quotes>Lex</quotes>));

F:=x[1,2]^3x[2,2]^2 + x[1,1]^3x[2,2]^2 + 1/4x[1,2];

DA.InitialOfDer(F, x[1,2]);
-------------------------------
x[2,2]^2
-------------------------------

DA.Initial

DA.DiffTO