Artifact 5c722ab6bff95b4d9817e1f1b8a61f4d822c40eb45430dab2ddf90905eb11aca:

• Executable file r37/packages/dipoly/dipvars.red — part of check-in [f2fda60abd] at 2011-09-02 18:13:33 on branch master — Some historical releases purely for archival purposes

  git-svn-id: https://svn.code.sf.net/p/reduce-algebra/code/trunk/historical@1375 2bfe0521-f11c-4a00-b80e-6202646ff360 (user: arthurcnorman@users.sourceforge.net, size: 594) [annotate] [blame] [check-ins using] [more...]

module dipvars;

%/* Determine distributive polynomial variables in a prefix form*/

%/*Authors: R. Gebauer, A. C. Hearn, H. Kredel*/

expr procedure dipvars u;
%   /* Returns list of variables in prefix form u*/
   dipvars1(u,nil);

expr procedure dipvars1(u,v);
   if atom u then if constantp u or u memq v then v else u . v
    else if idp car u and get(car u,'dipfn)
     then dipvarslist(cdr u,v)
    else if u memq v then v
    else u . v;

expr procedure dipvarslist(u,v);
   if null u then v
    else dipvarslist(cdr u,union(dipvars car u,v));

endmodule;

end;