From: gah@ugcs.caltech.edu   
      
   mac  wrote:   
   >> > should user be allowed to write multiple not   
      
   >> > not not not ( expr );   
   >> > not not  ( expr );   
      
   > Infamously, Algol 60 disallowed "not not", leading to an error   
   > message   not not not Algol.   
      
   I believe Fortran still doesn't allow it, though there have   
   been some changes over the years as to what is allowed.   
      
   Traditionally, two operators could not be adjacent, so that   
   unary negation following a binary operator required parentheses.   
   Nesting of unary operators (+, -, .NOT.) also required, and I   
   believe still does, parentheses.   
      
   I don't believe that the Fortran error message comes out a   
   above, though.   
      
   -- glen   
   [Depends on the compiler. -John]   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)