Richard already pointed out the wrong syntax (its different for system of equations as opposed to a single ODE) and that MC does not like the function FF, as you pass the functions you want to solve for as arguments.
Nevertheless you may pass the function values instead of the functions themselves which makes it work.
Richard Jackson wrote:
Nevertheless you may pass the function values instead of the function itself to make it work.
I didn't even think to try that. In fact, I would argue that it should not work. If the function has function names as arguments, then passing it values should throw an error.
Of course I had to change the function FF, too, so the arguments are scalars now 🙂
The argument "t" is obsolete now, I just forgot to delete it.
The argument "t" is obsolete now, I just forgot to delete it.
Ah. Sneaky. I think you didn't delete it just to catch me out 
