The invention provides a method of modifying a hierarchical integrated circuit layout wherein the locations of hierarchical layout elements are represented with variables and formulae using these variables, which produces a formula-based hierarchical layout. These variables are constrained to be integers. The invention provides for a method for guiding the modification of the layout through an objective function defined on the same variables as the formula-based hierarchical layout. The invention simplifies the formula-based hierarchical layout by substituting constants for some of the variables, such that each of the formulae are reduced to expressions involving no more than two remaining variables. This produces a simplified layout equation and a simplified objective function. This also produces a partial solution to the hierarchical layout modification made up of the values selected for the constants.