3.7.69. Cost matrix

A constraint for which a first argument corresponds to a collection of variables 𝚅𝚊𝚛𝚜, a second argument to a cost matrix 𝙼, and a third argument to a cost variable 𝙲. Let 𝚅𝚊𝚕𝚜 denote the set of values that can be assigned to the variables of 𝚅𝚊𝚛𝚜. The cost matrix defines for each pair v,u (v𝚅𝚊𝚛𝚜,u𝚅𝚊𝚕𝚜) an elementary cost, which is used for computing 𝙲 when value u is assigned to variable v.