QFFLWR(L,V)
[Quantifier-free formula list write.  L is a list of quantifier
free formulas in r variables, r>=1.  V is a variable list of length r.
The formulas in L are special written in the output stream.]
     safe L',L1.
(1)  L'=L;  while L'~=() do { ADV(L';L1,L');  QFFWR(L1,V) };
     return..