# ApCoCoA-1:DA.LD

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## DA.LD

the leading derivative of a differential polynomial

### Syntax

DA.LD(F:POLY):POLY

### Description

DA.LD computes the leading derivative of polynomial F wrt. the current differential term ordering, or the hereby induced ranking respectivly.

@param F A differential polynomial.

@return The leading derivative of F.

#### Example

Use Q[x[1..2,0..20]]; Use Q[x[1..2,0..20]], Ord(DA.DiffTO("DegOrd")); F:=x[1,2]^2*x[1,1]-x[2,4]^3; DA.LD(F); ------------------------------- x[2,4] -------------------------------