Creating an equation library (Updated 03-FEB-2017)

[akmon]

Thank you Han, for this improvement. I´ve tested it in another thread with positive results.
Now the bad news. Don´t know why but after calculations, I press the app icon for start the program again, and it restart the calculator. There is some kind of variable stored that corrupt the system. Mu version is the newest on physical calculator. So the first time has worked flawlessly, the second or next, restart.