Computing the partial derivatives of an element of the coordinate ring
of a chart in a recursive fashion skipping zero derivatives.
The procedure uses the global variables: desingSingS,
desingSingIND, desingSingPDER, which store the data
of the chart for F. The partial derivatives of f up to order b-1
will be generated in the global variable desingSingSL.
- a pair (f,b) where f is an element of the coordinate
ring of some underlying chart and b is a nonnegative integer,
- differentiating parameter indicator (in the subtree of
recursive calls only partial derivatives with respect to
parameters with index greater than or equal to t are used), in
the initial call it should be 1.