Singular

LIB "difform.lib";
ring R = 11,(u,v,w,x),lp;
diffAlgebra();
==> // The differential algebra Omega_R was constructed and the differential \
   forms du, dv, dw, dx are available.
/////////////////////////////////////
// Construction of structure lists //
/////////////////////////////////////
list L_1;
L_1[1] = list(du,dv,dw,dx);
L_1[2] = list(u,v,w,x);
list L_2;
L_2[1] = list(dx,dw,du,dv);
L_2[2] = list(x2,w2,u2,v-wu);
/////////////////////////////////
// Construction of derivations //
/////////////////////////////////
derivation phi = derivationFromList(L_1); phi;
==>  Omega_R^1 --> R
==>        du |--> u
==>        dv |--> v
==>        dw |--> w
==>        dx |--> x
==> 
==> 
derivation psi = derivationFromList(L_2); psi;
==>  Omega_R^1 --> R
==>        du |--> u2
==>        dv |--> -uw+v
==>        dw |--> w2
==>        dx |--> x2
==> 
==> 
kill Omega_R,du,dv,dw,dx,phi,psi,L_1,L_2;