Changed formula calculation. Calculated values are kept until an edit changes a cell they depend on; the edited cell and its dependents are then recalculated in dependency order, so a cell read by many formulas is calculated once. Every cell in a circular reference shows #ERROR!. One pass evaluates up to 100,000 formula cells or 200 milliseconds and follows at most 100 uncalculated references in one chain; cells left over show #ERROR! until the following pass, which starts immediately. Long reference chains that previously could stop the page with a stack overflow now calculate in passes.
Changed how Spreadsheets recalculate formulas
An edit now recalculates only the formulas that depend on it, in dependency order, with published limits per pass.