UniformDistribution initialMU = new UniformDistribution(score,range);

                // an algorithmic version of the following equation
                // mu[cell] = ( MU - intersectionArea[cell1] x mu[cell1] ... - intersectionArea[cellN] x mu[cellN]) / intersectionArea[cell]

                for (S2CellId cellOuter: cells) {
                        UniformDistribution mus = new UniformDistribution(initialMU);
                        for (S2CellId cellInner: cells) {
                                // if not cell from outer loop
                                if (!cellOuter.equals(cellInner))
                                {
                                        double areaInner = getIntersectionArea(thisField,cellInner);
                                        UniformDistribution cellInnerMU = getMU(cellInner);

                                        if (cellInnerMU != null)
                                        {
                                                UniformDistribution cma = cellInnerMU.mul(areaInner);
                                                mus = mus.sub(cma);
                                        }
                                        else
                                        {
                                                mus.setLower(0.0);
                                        }
                                }
                        }
                        double areaOuter = getIntersectionArea(thisField,cellOuter);
                        mus=mus.div(areaOuter);
                        mus.clampLower(0.0);

                        UniformDistribution cellOuterMU = getMU(cellOuter);

                        // refine UD:cello with mus

                        if (cellOuterMU == null)
                        {
                                cellOuterMU = mus;
                        }
                        else
                        {
                                try {
                                        if (cellOuterMU.refine(mus)){
                                                System.out.println("" + cellOuter.toToken() + "->" + cellOuterMU.toString());
                                                // add cell to modified array
                                        }
                                } catch (Exception e) {
                                        ; // something something, out of range error
                                }
                        }

                        // end refine UD:cello
                        putMU(cellOuter,cellOuterMU);
                }