Method of least squares - general and in tinme-rows - with extended mathematical proofs

Neuss: Bruno Buike 2008, 59p. - (Marburg: Tectum microfiche 1996 – ISBN 3-89608-865-3) - In coursebooks the proof for regression / method of least squares (without regress to probability) is given in some 9 or 10 lines. This mathematicians think sufficient - because EVERYBODY knows by him- or herself, that there is a PARTIAL DIFFERENTIATION plus a complex equations-system with 2 unkowns plus some other things, so that in the end we had some 4 pages Din A 4 with more than 40 single lines. - just for the BASIC theoreme.- It is apllied a) arithmetic notation, mainly from school-mathematics and b) formal logics in Russel-Whitehead-notation - There is a chapter with OTHER GRAPHS, than just the normally known linear graphs - WHICH HAS A BEARING on especially the TRAINING of PROPER MATHEMATICAL THINKING. - In these Corona--times it may be hinted to books with titles similar to: "Lying with statistics". adittionally ... - Otherwise it is my STRICT BELIEF, that we should not give intelligent folks "cooking recipes" to be handled mechanically, but to have the CRITICAL mind applied. Of course your BOSS will tell you other! So do the homework - at home ... and wonder, what insights may evolve ... I myself after this elaboration had to leave university without finals, because this paper was rejected - very probably OUT OF FEAR , that students might not show off TOO MUCH intelligence ..