From: nma@12000.org   
      
   On 4/17/2017 12:32 PM, Axel Vogt wrote:   
   > assume(x::real, 0 <> x); # getassumptions(x);   
   >   
   > ln(x^2)-2*ln(abs(x));   
   > combine(%); simplify(%) ;   
   >   
   >                                  ln(1)   
   >                                    0   
   >   
   > or you do it for each x < 0, 0 < x   
   >   
      
   Thanks, But the assumption of 0<>x is not really needed?   
      
   The trick is in the use of combine() to make it work as you   
   showed, and it works with just assuming x is real only.   
      
   restart;   
   assume(x::real);   
   simplify( combine(ln(x^2)-2*ln(abs(x))));   
      
              0   
      
   I do not understand Maple sometimes. Why using combine()   
   before simplify() made it work? Should this have been   
   simplified to 0 without having to tell Maple to combine first?   
      
   I do know that Maple likes to only do what it was told to   
   do and no less and no more. This sometimes is actually good.   
   But in this case, it means the user had to know to use   
   combine before simplify, which is something one would normally   
   expect to do.   
      
   I am using 2016.2 on windows.   
      
   --Nasser   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)