Universal structure of jet space
1. The operator D (of total derivative) in infinite jet space is a linear vector field. Exponential law determines his flow.
2. The same exponential law permits to calculate invariants of D.
3. The Lie field P (infinitesimal symmetry of D) can be studied in three different basis:
a) in natural basis after Lie-Olver , approach classic,
b) in adapted basis after Vinogradov , approach with contact forms and generating functions,
c) in invariant basis .
The exponential law promises a new invariant method for study of differential operators and equations and singularities.