“…The problem of the extraction of low energy ππ -interaction parameters with a desirable accuracy looks, in such a situation, extremely difficult. At the same time, the successive resolution of this problem is important by its own, irrespective of the following application of the results: the pion, which is the lightest hadron, participates -really or virtually -in every strong interaction process (see, for example, [28,31,32]). This is a reason why the complete phenomenological analysis of the data on low energy πN → ππN reaction is really of actual interest.…”