Singular

D.15.12.3 diffAlgebraCheck

Side effects:

Checks if the basering has a differential algebra and aborts with an error if this is not the case

Remarks:

The procedure checks if the name in the attribute attrib(basering,"diffAlgebra") is not empty. This is the case if the procedure diffAlgebra was executed first.

Note:

whenever computations with differential forms are done, it should be checked if the differential algebra was already generated since differential forms are polynomials in the differential algebra