From: nma@12000.org   
      
   What should CAS do when asked to integrate a dirac delta   
   over the real line when its argument is never zero on   
   the real line?   
      
   There is no solution for 2-cos(t)=0 on real line.   
      
   Maple 18:   
   int( Dirac(2-cos(t)),t=-infinity..infinity);   
   =========> unevaluated   
      
   Mathematica 9.01   
   Integrate[DiracDelta[2 - Cos[t]], {t, -Infinity, Infinity}]   
   =======>  0   
      
   What does your CAS produce? Another different behavior   
      
   Maple:   
   int( Dirac(I*t),t=-infinity..infinity);   
      ======> 1   
      
   and no Mathematica's turn to return unevaluated answer   
      
   Integrate[DiracDelta[I t], {t, -Infinity, Infinity}]   
   =====> remains unevaluated   
      
      
   --Nasser   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)