# Difference between revisions of "ApCoCoA-1:DA.Sep"

From ApCoCoAWiki

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− | DA.Sep returns the separand of polynomial F wrt. the current differential term ordering, or the hereby induced ranking, | + | DA.Sep returns the separand of polynomial F wrt. the current differential term ordering, or the hereby induced ranking, respectively. The seperand of F is just the initial of the derivative of F. |

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<example> | <example> | ||

− | Use | + | Use QQ[x[1..2,0..20]]; |

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

## Revision as of 11:06, 28 April 2009

## DA.Sep

Computes the separand of a differential polynomial.

### Syntax

DA.Sep(F:POLY):POLY

### Description

DA.Sep returns the separand of polynomial F wrt. the current differential term ordering, or the hereby induced ranking, respectively. The seperand of F is just the initial of the derivative of F.

@param

*F*A differential polynomial.@return The seperand of F wrt. to the current differential term ordering.

#### 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]; G:=DA.Differentiate(F); DA.Initial(G); ------------------------------- 2x[1,2]^3x[2,2] + 2x[1,1]^3x[2,2] ------------------------------- DA.Sep(F); ------------------------------- 2x[1,2]^3x[2,2] + 2x[1,1]^3x[2,2] -------------------------------