difference parameter that is the difference in height between the p and q material ratio, where p < q, in other words height difference between two material ratios, erinevusparameeter, mis on materjalisuhte p ja q kõrgusevahe, kus p < q, ehk teisisõnu kahe materjalisuhte kõrguse vaheparameeter, parameter that is the difference between two intersection levels of given material ratio p and q