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diff --git a/gsl-1.9/permutation/permutation.c b/gsl-1.9/permutation/permutation.c
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+/* permutation/permutation.c
+ *
+ * Copyright (C) 1996, 1997, 1998, 1999, 2000 Brian Gough
+ *
+ * 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 2 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.
+ */
+
+#include <config.h>
+#include <gsl/gsl_errno.h>
+#include <gsl/gsl_permutation.h>
+
+size_t
+gsl_permutation_size (const gsl_permutation * p)
+{
+ return p->size ;
+}
+
+size_t *
+gsl_permutation_data (const gsl_permutation * p)
+{
+ return p->data ;
+}
+
+#ifndef HIDE_INLINE_STATIC
+size_t
+gsl_permutation_get (const gsl_permutation * p, const size_t i)
+{
+ if (gsl_check_range)
+ {
+ if (i >= p->size) /* size_t is unsigned, can't be negative */
+ {
+ GSL_ERROR_VAL ("index out of range", GSL_EINVAL, 0);
+ }
+ }
+
+ return p->data[i];
+}
+#endif
+
+int
+gsl_permutation_swap (gsl_permutation * p, const size_t i, const size_t j)
+{
+ const size_t size = p->size ;
+
+ if (i >= size)
+ {
+ GSL_ERROR("first index is out of range", GSL_EINVAL);
+ }
+
+ if (j >= size)
+ {
+ GSL_ERROR("second index is out of range", GSL_EINVAL);
+ }
+
+ if (i != j)
+ {
+ size_t tmp = p->data[i];
+ p->data[i] = p->data[j];
+ p->data[j] = tmp;
+ }
+
+ return GSL_SUCCESS;
+}
+
+
+int
+gsl_permutation_valid (gsl_permutation * p)
+{
+ const size_t size = p->size ;
+
+ size_t i, j ;
+
+ for (i = 0; i < size; i++)
+ {
+ if (p->data[i] >= size)
+ {
+ GSL_ERROR("permutation index outside range", GSL_FAILURE) ;
+ }
+
+ for (j = 0; j < i; j++)
+ {
+ if (p->data[i] == p->data[j])
+ {
+ GSL_ERROR("duplicate permutation index", GSL_FAILURE) ;
+ }
+ }
+ }
+
+ return GSL_SUCCESS;
+}
+
+void
+gsl_permutation_reverse (gsl_permutation * p)
+{
+ const size_t size = p->size ;
+
+ size_t i ;
+
+ for (i = 0; i < (size / 2); i++)
+ {
+ size_t j = size - i - 1;
+
+ size_t tmp = p->data[i] ;
+ p->data[i] = p->data[j] ;
+ p->data[j] = tmp ;
+ }
+}
+
+int
+gsl_permutation_inverse (gsl_permutation * inv, const gsl_permutation * p)
+{
+ const size_t size = p->size ;
+
+ size_t i ;
+
+ if (inv->size != size)
+ {
+ GSL_ERROR("permutation lengths are not equal", GSL_EBADLEN);
+ }
+
+ for (i = 0; i < size; i++)
+ {
+ inv->data[p->data[i]] = i ;
+ }
+
+ return GSL_SUCCESS ;
+}
+
+int
+gsl_permutation_next (gsl_permutation * p)
+{
+ /* Replaces p with the next permutation (in the standard lexicographical
+ * ordering). Returns GSL_FAILURE if there is no next permutation.
+ */
+ const size_t size = p->size;
+ size_t i, j, k;
+
+ if (size < 2)
+ {
+ return GSL_FAILURE;
+ }
+
+ i = size - 2;
+
+ while ((p->data[i] > p->data[i+1]) && (i != 0))
+ {
+ i--;
+ }
+
+ if ((i == 0) && (p->data[0] > p->data[1]))
+ {
+ return GSL_FAILURE;
+ }
+
+ k = i + 1;
+
+ for (j = i + 2; j < size; j++ )
+ {
+ if ((p->data[j] > p->data[i]) && (p->data[j] < p->data[k]))
+ {
+ k = j;
+ }
+ }
+
+ /* swap i and k */
+
+ {
+ size_t tmp = p->data[i];
+ p->data[i] = p->data[k];
+ p->data[k] = tmp;
+ }
+
+ for (j = i + 1; j <= ((size + i) / 2); j++)
+ {
+ size_t tmp = p->data[j];
+ p->data[j] = p->data[size + i - j];
+ p->data[size + i - j] = tmp;
+ }
+
+ return GSL_SUCCESS;
+}
+
+int
+gsl_permutation_prev (gsl_permutation * p)
+{
+ const size_t size = p->size;
+ size_t i, j, k;
+
+ if (size < 2)
+ {
+ return GSL_FAILURE;
+ }
+
+ i = size - 2;
+
+ while ((p->data[i] < p->data[i+1]) && (i != 0))
+ {
+ i--;
+ }
+
+ if ((i == 0) && (p->data[0] < p->data[1]))
+ {
+ return GSL_FAILURE;
+ }
+
+ k = i + 1;
+
+ for (j = i + 2; j < size; j++ )
+ {
+ if ((p->data[j] < p->data[i]) && (p->data[j] > p->data[k]))
+ {
+ k = j;
+ }
+ }
+
+ /* swap i and k */
+
+ {
+ size_t tmp = p->data[i];
+ p->data[i] = p->data[k];
+ p->data[k] = tmp;
+ }
+
+ for (j = i + 1; j <= ((size + i) / 2); j++)
+ {
+ size_t tmp = p->data[j];
+ p->data[j] = p->data[size + i - j];
+ p->data[size + i - j] = tmp;
+ }
+
+ return GSL_SUCCESS;
+}
+
+int
+gsl_permutation_mul (gsl_permutation * p, const gsl_permutation * pa, const gsl_permutation * pb)
+{
+ size_t i;
+ const size_t size = p->size;
+
+ if (pa->size != size)
+ {
+ GSL_ERROR("size of result does not match size of pa", GSL_EINVAL);
+ }
+
+ if (pb->size != size)
+ {
+ GSL_ERROR("size of result does not match size of pb", GSL_EINVAL);
+ }
+
+ for (i = 0; i < size; i++)
+ {
+ p->data[i] = pb->data[pa->data[i]];
+ }
+
+ return GSL_SUCCESS;
+}
+int
+gsl_permutation_memcpy (gsl_permutation * dest,
+ const gsl_permutation * src)
+{
+ const size_t src_size = src->size;
+ const size_t dest_size = dest->size;
+
+ if (src_size != dest_size)
+ {
+ GSL_ERROR ("permutation lengths are not equal", GSL_EBADLEN);
+ }
+
+ {
+ size_t j;
+
+ for (j = 0; j < src_size; j++)
+ {
+ dest->data[j] = src->data[j];
+ }
+ }
+
+ return GSL_SUCCESS;
+}
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