Nodar Berikashvili

The Second Obstruction Functor

A functor responsible for second obstruction problems is defined and investigated on the category of topological spaces. In terms of this functor we formulate and prove a classification theorem for maps, which is the reformulation of all known classification theorems for the second obstruction.

Obstruction, homotopy, cohomology, cochain operation, $k$-invariant.

MSC 2000: 55Q25, 55S20, 55S35, 55S37, 55S45