PDO

先上张代码的图吧！FriCAS 虽然是从 AXIOM 这门古董级语言中 fork 出来的一个分支，目前仍处在活跃开发期，但是很多功能仍然缺失，尤其是：调试的功能基！...

For years, the computation of Lax equations is a tedious and time-consuming task. For example, KdV equation has the following type of Lax equation: ```mathjax L_t = [A, L], ``` where ```mathjax L=\partial^2+u(x,t)```, (A=\partial^3+4u(x,t)\partial+2u_x). Having been a graduate student majoring in integrable systems for years, I always had to work on such kind of computations. It was frustrating. At that time, I was thinking of a way to speed up the computation with the power of computers....