if (iTimeIndex > 0 || prevHiddenUnitActivation != null) { //For time == 0 && no prevMemCellState, equivalent to muli by 0
                    //Note that prevHiddenUnitActivations may be non-null at t=0 for TBPTT
                    //Again, deltaifog_current == deltaifogNext at this point... same array
                    Nd4j.gemm(prevLayerActivationSlice, deltaifogNext, iwGradientsOut, true, false, 1.0, 1.0);
                } else {