In order to introduce the new methodology, let us consider a study published in *Science* by Peter Gordon (see [@Gordon]) where he describes a primitive tribe living in Amazonia – Pirahã – that uses a very simple numeral system for counting: one, two, many. For Pirahã, all quantities larger than two are just ‘many’ and such operations as 2+2 and 2+1 give the same result, i.e., ‘many’. Using their weak numeral system Pirahã are not able to see, for instance, numbers 3, 4, and 5, to execute arithmetical operations with them, and, in general, to say anything about these numbers because in their language there are neither words nor concepts for that.

It is important to emphasize that the records $ 2+1=\mbox{`many'}$ and $2+2= \mbox{`many'}$ are correct in their language and if one is satisfied with the accuracy of the answer ‘many’, it can be used (and *is used* by Pirahã) in practice. Note that also for us, people knowing that $2+1=3$ and $2+2=4$, the result of Pirahã is not wrong, it is just *inaccurate*. Thus, if one needs a more precise result than ‘many’, it is necessary to introduce a more powerful mathematical language (a numeral system in this 