Hi everybody.

I'm using Maple these days to generate C code. More precisely, I use Maple to calculate high order derivatives. For example, I know that :

dt( u(x,t) ) = a(x) * dx( u(x,t) ) + b(x) * dx( p(x,t) )

dt( p(x,t) ) = c(x) * dx( p(x,t) ) + d(x) * dx( u(x,t) )

and I ask Maple to calculate the 5th time-derivative of u using these 2 properties. But in fact, I use 8 variables instead of 2 and PDEs are far more complicated.

Finally, I get thanks to Maple expressions of time-derivatives for my 8 variables.

Hi, I'm traying to maje a double integrate of P(A(t+Deltat),A(t)) , the first one in in untion of dA(t) and the second one is in fuction of dA(t+ DeltaT). How can I indicate in Maple Deltat?  Is it possible to integrate in function of A(t)?

All variables are constant, except A(t) and A(t + Deltat),

> F:=proc()