This function changes the format of the result table. Normally, every column of a solution stands for one attribute of the demands and supplies in the result table. Every row of a solution stands for an allocation with its demand and supply, where every column contains the allocation's value of the corresponding attribute. This function takes a list of attributes and replaces the columns meaning of the result table. In this case every column contains all allocations of a value combination of the given attributes.

This in turn allows one to represent the output in a more compact and readable way. In order to understand this formatting, it is best to just try it out. It is best to use this formating function in combination with  the function rowAttributesForOutputFormat   .