(I'm french, scuse me about my bad english)

Hi everyone, 

I'm new with maple and I have a big question. I tried really hard for 2 days to find the answer but... 

My problem it's really simple, i think...

this is the end of the program where is my problem:

      dsn1 := dsolve(dfin, numeric); 

      dsn1(1);

      proc(x_rkf45)  ...  end;