Direkter Summand/Polynomring/Standardgraduiert/Differentiell ausdehnbar/Signatur/Fakt/en

Let be an -graded -subalgebra of the standard-graded polynomial ring. Suppose that this inclusion is a direct summand which is also differentially extensible.

Then

and

where . The differential signature of equals its degree (as a graded ring), it is a rational number and the defining sequence converges.