  The Kontsevich-Soibelman solution of the cyclic version of Deligne's
conjecture and the formality of the operad of little discs on a cylinder
provide us with a natural homotopy calculus structure on the pair (C^*(A),
C_*(A)) ``Hochschild cochains + Hochschild chains'' of an associative algebra
A. We show that for an arbitrary smooth algebraic variety X with the structure
sheaf O_X the sheaf (C^*(O_X), C_*(O_X)) of homotopy calculi is formal. This
result was announced in paper [29] by the second and the third author.
