ABSTRACT
Elementary properties of Fourier transformation allow us to write for φ ∈ S D α φ ^ ( ξ ) = ξ α φ ^ ( ξ ) , https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780203758540/6d885673-f289-4121-8af1-b07f3a2f9acf/content/eq197.tif"/>
