http://hsm.stackexchange.com/questions/3323/who-invented-the-leibnitz-notation-fracd2ydx2-for-the-second-derivati?newsletter=1&nlcode=531872%7cdaae


d/dy=d/dx*dx/dy
this is a conventional equation as math geometry as you know,
but not perfected understood by advocater, Leibnitz, i've heard of it for sure.


yes, not only by experience only, but also, dedution could help us going straight on our decent, happy way, as we hope it,

well, the last part i'd said is a common and private way,
but i hope both- in math world and also our daily world- will make together happier than present staple way//


oh, i should say more clearly, must share more merry, fantastic time to feel easy like at home!!


*its my short conversation exercise, not using dictionary( sorry for my mis-typos.)


ellie