A new geometrical structure is proposed for a differential complex of the Koszul type. The
generators of the complex are structured on more levels and new graduations are used. A
generalized differential that can be split in many pieces acts on the generators. The first two
items are identified with the Koszul operators from the sp (2) BRST quantization. This result
suggests the possibility of the implementation of a symmetry bigger than sp (2). The third
order Koszul differential is effectively constructed. As an application of this construction, the …