  A discrete (finite-difference) analogue of differential forms is considered,
defined on simplicial complexes, including triangulations of continuous
manifolds. Various operations are explicitly defined on these forms, including
exterior derivative and exterior product. The latter one is non-associative.
Instead, as anticipated, it is a part of non-trivial A-infinity structure,
involving a chain of poly-linear operations, constrained by nilpotency
relation: (d + \wedge + m + ...)^n = 0 with n=2.
