Important: The diffalg package has been deprecated. Use the superseding package DifferentialAlgebra instead.

The command differentiate computes the successive derivatives of the differential polynomial  q that belongs to R according to the  elements of ders. The elements of ders must be derivations of R.

The command with(diffalg,differentiate) allows the use of the abbreviated form of this command.

$\mathrm{with}\left(\mathrm{diffalg}\right)\:$

$R≔\mathrm{differential\_ring}\left(\mathrm{derivations}=\left[x\,y\right]\,\mathrm{ranking}=\left[u\,v\right]\right)$

$R≔\mathrm{PDE\_ring}$

$\mathrm{differentiate}\left({u\left[x,x\right]}^2+u\left[x\right]\,x\,R\right)$

$2u_{x,x}{u}_{x,x,x}+u_{x,x}$

$\mathrm{differentiate}\left(u\left[x,y\right]\,x\,y\,R\right)$

$u_{x,x,y,y}$