I have a problem, to which I think the solution is to make ln(x) inert.  I'd like to be able to enter the following

diff(1.5^x,x);

and get back 

ln(1.5)1.5^x

But of course Maple returns 

It seems to me that if I could make ln(x) inert for that might work, but I don't really know much about the ToInert command.  Or maybe this isn't the right approach.