GBNP.OptionsRec, accessed via GBNP.GetOption, GBNP.SetOption etc. in
options.gi, contains the following names:

pg : number of prefix (module) generators, 0 for two-sided ideals; set
    by GP2NPM, SGrobnerModule and the Gröbner basis loop
PrintLetterFunction : set by GBNP.ConfigPrint
PrintModuleDimension : set by GBNP.ConfigPrint
PrintModuleGenerators : number of module generators for PrintNP; if
    unset, pg is used
Alphabetsize : the number of generators
CancellativeMonoid : if bound then g_i(w1+w2+...+w_i)=0 -> w1+w2+...+w_i=0
    (same for (w1+w2+...+w_i)g_i ) (if i>1)
    requires Alphabetsize
    NOTE: g_i+n will be used for the cancellation of g_i
    (make sure to set up algebras and GBNP.ConfigPrint accordingly)
CheckQA : if bound, the Gröbner basis loop reports the size of the
    quotient algebra up to this bound in each iteration; requires
    Alphabetsize
lenGB : number of elements of the Gröbner basis already treated
PrintTraceAsGP : if Algebra is also set, print the trace as GP
Algebra : the FreeAssociativeAlgebraWithOne corresponding to the relations
cleancount : clean the Gröbner basis with itself every cleancount
    iterations (unset or 0: never)
cleanpolys : if bound, clean the Gröbner basis with itself after the
    next iteration
