/* specfunc/gsl_sf_lambert.h

 * 

 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001 Gerard Jungman

 * 

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 3 of the License, or (at

 * your option) any later version.

 * 

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * General Public License for more details.

 * 

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 */

/* Author:  G. Jungman */

#ifndef __GSL_SF_LAMBERT_H__

#define __GSL_SF_LAMBERT_H__

#include <gsl/gsl_sf_result.h>

#undef __BEGIN_DECLS

#undef __END_DECLS

#ifdef __cplusplus

# define __BEGIN_DECLS extern "C" {

# define __END_DECLS }

#else

# define __BEGIN_DECLS /* empty */

# define __END_DECLS /* empty */

#endif

__BEGIN_DECLS

/* Lambert's Function W_0(x)

 *

 * W_0(x) is the principal branch of the

 * implicit function defined by W e^W = x.

 *

 * -1/E < x < \infty

 *

 * exceptions: GSL_EMAXITER;

 */

int     gsl_sf_lambert_W0_e(double x, gsl_sf_result * result);

double  gsl_sf_lambert_W0(double x);

/* Lambert's Function W_{-1}(x)

 *

 * W_{-1}(x) is the second real branch of the

 * implicit function defined by W e^W = x.

 * It agrees with W_0(x) when x >= 0.

 *

 * -1/E < x < \infty

 *

 * exceptions: GSL_MAXITER;

 */

int     gsl_sf_lambert_Wm1_e(double x, gsl_sf_result * result);

double  gsl_sf_lambert_Wm1(double x);

__END_DECLS

#endif /* __GSL_SF_LAMBERT_H__ */