APWRL(S_)
[Algebraic point write, linear.  S_ is an algebraic point in
r-dimensional space, for some r>=1, or NULL. If S_==NULL, then
nothing written in the output stream.  Otherwise, the primitive
element alpha of S_, followed by the coordinate r-tuple of S_
(an r-tuple of elements of Q(alpha))
is written to the output stream.  All polynomials are written in linear
format. Currently sample point construction times not written.]
     const NULL=0.
     safe i,M,b,b1,J,r.
(1)  U=LIST1("U");
     if S_~=NULL then {  FIRST3(S_;M,b,J);
     clout("PRIMITIVEELEMENT");  emptob;
     ANWRL(M,J,U);
     clout("POINT");  emptob;
     cwrite('(');  emptob;
     r=LENGTH(b);  b'=b;  for i=1,...,r do
     { ADV(b';b1,b');  cwrite('(');  RPSWL(b1,U); 
     cwrite(')');  emptob };
     cwrite(')');  emptob  };
     return..