\\% Auxiliary function for eta.gpi, theta.gpi, lambert.gpi
\\ Author: Joerg Arndt
\\ License: GPL version 3 or later
\\ online at http://www.jjj.de/pari/
\\ version: 2011-August-04 (07:55)


chkS_(S)=
{
    if ( S==-1,  \\ arg S was omitted
        if ( ell_S_ != 'ell_S_,  \\ supplied as global variable?
            return( ell_S_ );
        , /* else */
            error("supply S>=0 as last argument");
        );
    );
    return( S );
} /* ----- */

\\ ==== end of file ====