Dearl All, I recently bought the book that I studied in my PhD years. It is "*Differential Equations: their solution using symmetries*" by Hans Stephani. https://www.amazon.com/Differential-Equations-Their-Solution-Symmetries/dp/0521355311/ref=sr_1_1?dchild=1&keywords=hans+stephani+differential+equation&qid=1591870417&sr=8-1
In the book, methods to solve nonlinear ODE's or PDE's are given if the differential equation has an underlying Lie group symmetry. I remember using the program "Reduce" in the course. It may be useful. My aim is to incorporate the methods given in the book to Sage Math. So if you are interested maybe we can form a small group to contribute to Sage in this respect. I believe the ability to solve complex differential equations is quite important for a symbolic math software. Please let me know if you are interested. Best regards, -- F. Semih Dündar <f.semih.dun...@gmail.com> -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-devel/CAODtkKqaSuaut047k2Ts7LkOmEboDqjMNqv%2BVVcJAosehYpLbw%40mail.gmail.com.