In certain MODFLOW packages, such as the Layer Property Flow package, it is possible to define "parameters" that are used in combination with "multiplier arrays" and "zone arrays" to define the spatial variability of some input data such as the hydraulic conductivity. When parameters are defined, ModelMuse will not allow the user to define a formula for the related data set. Instead, it will generate a formula that reproduces what MODFLOW will do in assigning values to the input data.