
D.15.12.45 derivationContractionGen
Procedure from library difform.lib (see difform_lib).
 Usage:
 derivationContractionGen(phi,d_gen); phi derivation, d_gen difform
 Assume:
 d_gen is a generator of the differential algebra
 Return:
 the image of d_gen under the contraction map i_phi
 Remarks:
 The formula for the contraction map applied to a generator of degree l is given by:
i_phi^(l)(dx_k*...*dx_j) = sum(i=1,..l)(1)^(i+1) * phi(dx_i) * (dx_k*...*dx_j / dx_i)
 Note:
 this procedure should only be applied to generators
See also:
derivationContraction.
