multi1d<DPropagator> dprop_slice = sumMulti(quark_propagator, ss.getSubset());
multi1d<Propagator> dprop_slice = sumMulti(quark_propagator, phases.getSubset());
void wall_qprop(LatticePropagator& wall_quark_prop, 		const LatticePropagator& quark_propagator, 		const SftMom& phases){  START_CODE("wall_qprop");  // Length of lattice in decay direction  int length  = ss.numSubsets();  int j_decay = ss.getDir();  // Project propagator onto zero momentum: Do a slice-wise sum.  multi1d<DPropagator> dprop_slice = sumMulti(quark_propagator, ss.getSubset());    // Now create the mask for 1 site per time slice  LatticeBoolean lbtmp1 = true;  for(int mu = 0; mu < Nd; ++mu)    if( mu != j_decay )      lbtmp1 &= (Layout::latticeCoordinate(mu) == 0);  for(int t = 0; t < length; ++t)    wall_quark_prop = where(lbtmp1 & (Layout::latticeCoordinate()[j_decay] == t),			    LatticePropagator(dprop_slice[t]),			    LatticePropagator(zero));              END_CODE("wall_qprop");}