Welcome to the Fractal Gallery and do not be concerned about your English I would say you do very well with writting it. As for knowing mathematics I doubt seriously if there is 12 people who actually knows mathematics here most have learned just like you are doing, trial and error :)plus there is a lot of great people here that I'm sure will be willing to help you learn more. This gallery is one of the best ones here at Rendo good people here. Welcome again hope to see some of your work soon Carolyn