diffalg

 return the difference between the derivation operators of the leaders of two differential polynomials

 Calling Sequence delta_leader (p, q, R)

Parameters

 p, q - differential polynomials R - differential polynomial ring

Description

 • Important: The diffalg package has been deprecated. Use the superseding package DifferentialAlgebra instead.
 • Let fp and fq denote the leaders of p and q. The function delta_leader returns a sequence, if it exists, of derivations s such that fp = differentiate (fq, s, R).
 • The function returns FAIL if p or q belongs to the ground field of R or if fp and fq are derivatives of different differential indeterminates.
 • The command with(diffalg,delta_leader) allows the use of the abbreviated form of this command.

Examples

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

 > $\mathrm{with}\left(\mathrm{diffalg}\right):$
 > $R≔\mathrm{differential_ring}\left(\mathrm{derivations}=\left[x,y\right],\mathrm{ranking}=\left[u\right]\right)$
 ${R}{≔}{\mathrm{PDE_ring}}$ (1)
 > $p≔{u}_{x,x,y}^{2}-4{u}_{[]}$
 ${p}{≔}{{u}}_{{x}{,}{x}{,}{y}}^{{2}}{-}{4}{}{{u}}_{{[}{]}}$ (2)
 > $q≔{u}_{x}$
 ${q}{≔}{{u}}_{{x}}$ (3)
 > $\mathrm{delta_leader}\left(p,q,R\right)$
 ${x}{,}{y}$ (4)