Beware not to buy HP Prime, if you are engineer!

[pier4r]

Dmmaster no I don't do the butter alone, but that is the base. I cook by myself. Cooking is like writing short recipes.

If you say "books of math in the past were great and today they are poor"(I disagree. There is a lot of math around in those days if you know what to look) and then at the same time you want to sell the idea that creating your equation library is hard, you create a contradiction. If you want to say that people that studied in the past put more effort and quality in their actions, then they have no need of ready made equation libraries as they are used to put a bit of effort.

Sorry but your argument is fighting itself in my view. Others have provided better points.