public override List <Matrix <T> > BackPropagate(List <Matrix <T> > targets, bool needInputSens = false) { List <Matrix <T> > prop = OutLayer.ErrorPropagate(targets); if (LayersList.Count < 2) { return(prop); } for (int i = LayersList.Count - 2; i > 0; i--) { var layer = LayersList[i]; prop = layer.BackPropagate(prop, true); } return(InLayer.BackPropagate(prop, needInputSens)); }