ABSTRACT
So, given a (~differentiable vector field X, if 0) (X) is a (~) differentiable function then 0) is differentiable.
Notation. A covector field or field of I-forms on M is an element of %" (M) = 0 1(M). We denote
0) E01(M) or
The properties of covector fields are similar to the ones ofvector fields.
