  We consider the double-spin cos(phi) asymmetry for pion electroproduction in
semi-inclusive deep inelastic scattering of longitudinally polarized leptons
off longitudinally polarized protons. We estimate the size of the asymmetry in
the approximation where all twist-3 interaction-dependent distribution and
fragmentation functions are set to zero. In that approximation at HERMES
kinematics a sizable negative cos(phi) double-spin asymmetry for pi+
electroproduction is predicted.
