@ernilesh80: If you want to use diff, then you cannot use t1 without an explicit argument T, for diff(t1,T) vanishes identically. [Technically, you could use the PDEtools:-declare command to have t1(T) shown as t1, but then diff(t1(T),T) will be shown as t1 with a lowered index T (socalled jet-notation, I believe); doing so would not be an improvement, I guess.]
I am having trouble nudging ap6 into ap7, even after having simplified it using the above mentioned beta::real assumption.
Update: You can find various manuals, both introductory and advanced level ones, by either 1.) performing a Google search for 'maple manual pdf', say; or 2.) going to the Maplesoft Documentation Center (although, surprisingly, the 'Maple Introductory Programming Guide' seems not be found there).
PS: You do not have to call me sir; just call me by my first name :-).