%mathpiper,def="ExpandUniVariate"

Function("ExpandUniVariate",{var,first,coefs})
[
  Local(result,i);
  result:=0;
  For(i:=Length(coefs),i>0,i--)
  [
    Local(term);
    term:=NormalForm(coefs[i])*var^(first+i-1);
    result:=result+term;
  ];
  result;
];

%/mathpiper