Interesting observation, hipow/2 can be used to check   
   whether a variable occurs in a polynomial.   
      
   So if I want to check whether the denumerator Q, contains   
   Z, I simply check hipow(Q,Z)<>0, right?   
      
   And I guess we also have:   
      
     listofvars(Q) = { V | hipow(Q,V) <> 0 }   
      
   But it wouldn't be implemented this way.   
      
   Am Dienstag, 11. Juli 2017 22:28:41 UTC+2 schrieb burs...@gmail.com:   
   > We can write p(X,Y,Z) along powers of Z (say hello   
   > to my new function hipow/2):   
      
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