PART I. INTRODUCTION AND PRELIMINARIES -- 1. Introduction -- 2. Eilenberg-MacLane groups and cohomology operations -- 3. Cohomology operations for the case of the second obstruction -- 4. Binary cohomology operations -- PART II. INVARIANTS FOR THE EXTENSION PROBLEM -- 5. The first level of invariants -- 6. The second level of invariants -- 7. The main extension theorems -- 8. A special case and the retraction theorem -- PART III. INVARIANTS FOR THE HOMOTOPY PROBLEM -- 9. The first level: Difference homomorphisms -- 10. The second level and the homotopy theorems
PART IV. PROPERTIES OF THE EXTENSION INVARIANT -- 11. General properties -- 12. Comparison formula -- 13. Coset structure and formula -- PART V. PROPERTIES OF THE HOMOTOPY INVARIANT -- 14. General properties -- 15. Addition formula and its consequences -- formula for Nf, f -- 16. An application -- 17. Appendix 1: More general definition of the invariants -- 18. Appendix 2: Some homological information -- 19. Appendix 3: Mapping Cylinders -- BIBLIOGRAPHY
