%{
open FslexFsyacc
open PolynomialExpressions.Tokenizer
type token = PositionWith<Token>
%}
<index> = "**" INT
<sign>  = [ "+" "-" ]
%%
<sign>? INT { // multiline test
              toConst lexbuf }
<sign>? INT? ID <index>? { toTerm lexbuf }