  In this paper, the multiple access channel (MAC) with channel state is
analyzed in a scenario where a) the channel state is known non-causally to the
transmitters and b) there is perfect causal feedback from the receiver to the
transmitters. An achievable region and an outer bound are found for a discrete
memoryless MAC that extend existing results, bringing together ideas from the
two separate domains of MAC with state and MAC with feedback. Although this
achievable region does not match the outer bound in general, special cases
where they meet are identified.
  In the case of a Gaussian MAC, a specialized achievable region is found by
using a combination of dirty paper coding and a generalization of the
Schalkwijk-Kailath, Ozarow and Merhav-Weissman schemes, and this region is
found to be capacity achieving. Specifically, it is shown that additive
Gaussian interference that is known non-causally to the transmitter causes no
loss in capacity for the Gaussian MAC with feedback.
