Membrane source-probe dynamics is investigated in the framework of the fini
te N-sector DLCQ M-theory compactified on a transverse two-torus for an arb
itrary size of the longitudinal dimension. The non-perturbative two-fermion
terms in the effective action of the matrix theory, the (2 + 1)-dimensiona
l supersymmetric Yang-Mills theory, that are related to the four derivative
F-4 terms by the supersymmetry transformation are obtained, including the
one-loop term and full instanton corrections. On the supergravity side, we
compute the classical probe action up to two-fermion terms based on the cla
ssical supermembrane formulation in an arbitrary curved background geometry
produced by source membranes satisfying the BPS condition; two-fermion ter
ms correspond to the spin-orbit couplings for membranes. We find precise ag
reement between the two approaches when the background space-time is chosen
to be that of the DLCQ M-theory, which is asymptotically locally anti-de S
itter. (C) 1999 Elsevier Science B.V. All rights reserved.