text: /*  -- translated by f2c (version 20100827).
     You must link the resulting object file with libf2c:
  	on Microsoft Windows system, link with libf2c.lib;
  	on Linux or Unix systems, link with .../path/to/libf2c.a -lm
  	or, if you install libf2c.a in a standard place, with -lf2c -lm
  	-- in that order, at the end of the command line, as in
  		cc *.o -lf2c -lm
  	Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
  
  		http://www.netlib.org/f2c/libf2c.zip
  */
  
  #include "f2c.h"
  
  /* Table of constant values */
  
  static integer c__1 = 1;
  static doublereal c_b14 = 1.;
  static doublereal c_b25 = -1.;
  
  /* > \brief \b DLARFB applies a block reflector or its transpose to a general rectangular matrix.   
  
      =========== DOCUMENTATION ===========   
  
     Online html documentation available at   
                http://www.netlib.org/lapack/explore-html/   
  
     > \htmlonly   
     > Download DLARFB + dependencies   
     > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dlarfb.
  f">   
     > [TGZ]</a>   
     > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dlarfb.
  f">   
     > [ZIP]</a>   
     > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dlarfb.
  f">   
     > [TXT]</a>   
     > \endhtmlonly   
  
      Definition:   
      ===========   
  
           SUBROUTINE DLARFB( SIDE, TRANS, DIRECT, STOREV, M, N, K, V, LDV,   
                              T, LDT, C, LDC, WORK, LDWORK )   
  
           CHARACTER          DIRECT, SIDE, STOREV, TRANS   
           INTEGER            K, LDC, LDT, LDV, LDWORK, M, N   
           DOUBLE PRECISION   C( LDC, * ), T( LDT, * ), V( LDV, * ),   
          $                   WORK( LDWORK, * )   
  
  
     > \par Purpose:   
      =============   
     >   
     > \verbatim   
     >   
     > DLARFB applies a real block reflector H or its transpose H**T to a   
     > real m by n matrix C, from either the left or the right.   
     > \endverbatim   
  
      Arguments:   
      ==========   
  
     > \param[in] SIDE   
     > \verbatim   
     >          SIDE is CHARACTER*1   
     >          = 'L': apply H or H**T from the Left   
     >          = 'R': apply H or H**T from the Right   
     > \endverbatim   
     >   
     > \param[in] TRANS   
     > \verbatim   
     >          TRANS is CHARACTER*1   
     >          = 'N': apply H (No transpose)   
     >          = 'T': apply H**T (Transpose)   
     > \endverbatim   
     >   
     > \param[in] DIRECT   
     > \verbatim   
     >          DIRECT is CHARACTER*1   
     >          Indicates how H is formed from a product of elementary   
     >          reflectors   
     >          = 'F': H = H(1) H(2) . . . H(k) (Forward)   
     >          = 'B': H = H(k) . . . H(2) H(1) (Backward)   
     > \endverbatim   
     >   
     > \param[in] STOREV   
     > \verbatim   
     >          STOREV is CHARACTER*1   
     >          Indicates how the vectors which define the elementary   
     >          reflectors are stored:   
     >          = 'C': Columnwise   
     >          = 'R': Rowwise   
     > \endverbatim   
     >   
     > \param[in] M   
     > \verbatim   
     >          M is INTEGER   
     >          The number of rows of the matrix C.   
     > \endverbatim   
     >   
     > \param[in] N   
     > \verbatim   
     >          N is INTEGER   
     >          The number of columns of the matrix C.   
     > \endverbatim   
     >   
     > \param[in] K   
     > \verbatim   
     >          K is INTEGER   
     >          The order of the matrix T (= the number of elementary   
     >          reflectors whose product defines the block reflector).   
     > \endverbatim   
     >   
     > \param[in] V   
     > \verbatim   
     >          V is DOUBLE PRECISION array, dimension   
     >                                (LDV,K) if STOREV = 'C'   
     >                                (LDV,M) if STOREV = 'R' and SIDE = 'L'   
     >                                (LDV,N) if STOREV = 'R' and SIDE = 'R'   
     >          The matrix V. See Further Details.   
     > \endverbatim   
     >   
     > \param[in] LDV   
     > \verbatim   
     >          LDV is INTEGER   
     >          The leading dimension of the array V.   
     >          If STOREV = 'C' and SIDE = 'L', LDV >= max(1,M);   
     >          if STOREV = 'C' and SIDE = 'R', LDV >= max(1,N);   
     >          if STOREV = 'R', LDV >= K.   
     > \endverbatim   
     >   
     > \param[in] T   
     > \verbatim   
     >          T is DOUBLE PRECISION array, dimension (LDT,K)   
     >          The triangular k by k matrix T in the representation of the   
     >          block reflector.   
     > \endverbatim   
     >   
     > \param[in] LDT   
     > \verbatim   
     >          LDT is INTEGER   
     >          The leading dimension of the array T. LDT >= K.   
     > \endverbatim   
     >   
     > \param[in,out] C   
     > \verbatim   
     >          C is DOUBLE PRECISION array, dimension (LDC,N)   
     >          On entry, the m by n matrix C.   
     >          On exit, C is overwritten by H*C or H**T*C or C*H or C*H**T.   
     > \endverbatim   
     >   
     > \param[in] LDC   
     > \verbatim   
     >          LDC is INTEGER   
     >          The leading dimension of the array C. LDC >= max(1,M).   
     > \endverbatim   
     >   
     > \param[out] WORK   
     > \verbatim   
     >          WORK is DOUBLE PRECISION array, dimension (LDWORK,K)   
     > \endverbatim   
     >   
     > \param[in] LDWORK   
     > \verbatim   
     >          LDWORK is INTEGER   
     >          The leading dimension of the array WORK.   
     >          If SIDE = 'L', LDWORK >= max(1,N);   
     >          if SIDE = 'R', LDWORK >= max(1,M).   
     > \endverbatim   
  
      Authors:   
      ========   
  
     > \author Univ. of Tennessee   
     > \author Univ. of California Berkeley   
     > \author Univ. of Colorado Denver   
     > \author NAG Ltd.   
  
     > \date June 2013   
  
     > \ingroup doubleOTHERauxiliary   
  
     > \par Further Details:   
      =====================   
     >   
     > \verbatim   
     >   
     >  The shape of the matrix V and the storage of the vectors which define   
     >  the H(i) is best illustrated by the following example with n = 5 and   
     >  k = 3. The elements equal to 1 are not stored; the corresponding   
     >  array elements are modified but restored on exit. The rest of the   
     >  array is not used.   
     >   
     >  DIRECT = 'F' and STOREV = 'C':         DIRECT = 'F' and STOREV = 'R':   
     >   
     >               V = (  1       )                 V = (  1 v1 v1 v1 v1 )   
     >                   ( v1  1    )                     (     1 v2 v2 v2 )   
     >                   ( v1 v2  1 )                     (        1 v3 v3 )   
     >                   ( v1 v2 v3 )   
     >                   ( v1 v2 v3 )   
     >   
     >  DIRECT = 'B' and STOREV = 'C':         DIRECT = 'B' and STOREV = 'R':   
     >   
     >               V = ( v1 v2 v3 )                 V = ( v1 v1  1       )   
     >                   ( v1 v2 v3 )                     ( v2 v2 v2  1    )   
     >                   (  1 v2 v3 )                     ( v3 v3 v3 v3  1 )   
     >                   (     1 v3 )   
     >                   (        1 )   
     > \endverbatim   
     >   
      =====================================================================   
     Subroutine */ int igraphdlarfb_(char *side, char *trans, char *direct, char *
  	storev, integer *m, integer *n, integer *k, doublereal *v, integer *
  	ldv, doublereal *t, integer *ldt, doublereal *c__, integer *ldc, 
  	doublereal *work, integer *ldwork)
  {
      /* System generated locals */
      integer c_dim1, c_offset, t_dim1, t_offset, v_dim1, v_offset, work_dim1, 
  	    work_offset, i__1, i__2;
  
      /* Local variables */
      integer i__, j;
      extern /* Subroutine */ int igraphdgemm_(char *, char *, integer *, integer *, 
  	    integer *, doublereal *, doublereal *, integer *, doublereal *, 
  	    integer *, doublereal *, doublereal *, integer *);
      extern logical igraphlsame_(char *, char *);
      extern /* Subroutine */ int igraphdcopy_(integer *, doublereal *, integer *, 
  	    doublereal *, integer *), igraphdtrmm_(char *, char *, char *, char *, 
  	    integer *, integer *, doublereal *, doublereal *, integer *, 
  	    doublereal *, integer *);
      char transt[1];
  
  
  /*  -- LAPACK auxiliary routine (version 3.5.0) --   
      -- LAPACK is a software package provided by Univ. of Tennessee,    --   
      -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--   
         June 2013   
  
  
      =====================================================================   
  
  
         Quick return if possible   
  
         Parameter adjustments */
      v_dim1 = *ldv;
      v_offset = 1 + v_dim1;
      v -= v_offset;
      t_dim1 = *ldt;
      t_offset = 1 + t_dim1;
      t -= t_offset;
      c_dim1 = *ldc;
      c_offset = 1 + c_dim1;
      c__ -= c_offset;
      work_dim1 = *ldwork;
      work_offset = 1 + work_dim1;
      work -= work_offset;
  
      /* Function Body */
      if (*m <= 0 || *n <= 0) {
  	return 0;
      }
  
      if (igraphlsame_(trans, "N")) {
  	*(unsigned char *)transt = 'T';
      } else {
  	*(unsigned char *)transt = 'N';
      }
  
      if (igraphlsame_(storev, "C")) {
  
  	if (igraphlsame_(direct, "F")) {
  
  /*           Let  V =  ( V1 )    (first K rows)   
                         ( V2 )   
               where  V1  is unit lower triangular. */
  
  	    if (igraphlsame_(side, "L")) {
  
  /*              Form  H * C  or  H**T * C  where  C = ( C1 )   
                                                        ( C2 )   
  
                  W := C**T * V  =  (C1**T * V1 + C2**T * V2)  (stored in WORK)   
  
                  W := C1**T */
  
  		i__1 = *k;
  		for (j = 1; j <= i__1; ++j) {
  		    igraphdcopy_(n, &c__[j + c_dim1], ldc, &work[j * work_dim1 + 1],
  			     &c__1);
  /* L10: */
  		}
  
  /*              W := W * V1 */
  
  		igraphdtrmm_("Right", "Lower", "No transpose", "Unit", n, k, &c_b14,
  			 &v[v_offset], ldv, &work[work_offset], ldwork);
  		if (*m > *k) {
  
  /*                 W := W + C2**T * V2 */
  
  		    i__1 = *m - *k;
  		    igraphdgemm_("Transpose", "No transpose", n, k, &i__1, &c_b14, &
  			    c__[*k + 1 + c_dim1], ldc, &v[*k + 1 + v_dim1], 
  			    ldv, &c_b14, &work[work_offset], ldwork);
  		}
  
  /*              W := W * T**T  or  W * T */
  
  		igraphdtrmm_("Right", "Upper", transt, "Non-unit", n, k, &c_b14, &t[
  			t_offset], ldt, &work[work_offset], ldwork);
  
  /*              C := C - V * W**T */
  
  		if (*m > *k) {
  
  /*                 C2 := C2 - V2 * W**T */
  
  		    i__1 = *m - *k;
  		    igraphdgemm_("No transpose", "Transpose", &i__1, n, k, &c_b25, &
  			    v[*k + 1 + v_dim1], ldv, &work[work_offset], 
  			    ldwork, &c_b14, &c__[*k + 1 + c_dim1], ldc);
  		}
  
  /*              W := W * V1**T */
  
  		igraphdtrmm_("Right", "Lower", "Transpose", "Unit", n, k, &c_b14, &
  			v[v_offset], ldv, &work[work_offset], ldwork);
  
  /*              C1 := C1 - W**T */
  
  		i__1 = *k;
  		for (j = 1; j <= i__1; ++j) {
  		    i__2 = *n;
  		    for (i__ = 1; i__ <= i__2; ++i__) {
  			c__[j + i__ * c_dim1] -= work[i__ + j * work_dim1];
  /* L20: */
  		    }
  /* L30: */
  		}
  
  	    } else if (igraphlsame_(side, "R")) {
  
  /*              Form  C * H  or  C * H**T  where  C = ( C1  C2 )   
  
                  W := C * V  =  (C1*V1 + C2*V2)  (stored in WORK)   
  
                  W := C1 */
  
  		i__1 = *k;
  		for (j = 1; j <= i__1; ++j) {
  		    igraphdcopy_(m, &c__[j * c_dim1 + 1], &c__1, &work[j * 
  			    work_dim1 + 1], &c__1);
  /* L40: */
  		}
  
  /*              W := W * V1 */
  
  		igraphdtrmm_("Right", "Lower", "No transpose", "Unit", m, k, &c_b14,
  			 &v[v_offset], ldv, &work[work_offset], ldwork);
  		if (*n > *k) {
  
  /*                 W := W + C2 * V2 */
  
  		    i__1 = *n - *k;
  		    igraphdgemm_("No transpose", "No transpose", m, k, &i__1, &
  			    c_b14, &c__[(*k + 1) * c_dim1 + 1], ldc, &v[*k + 
  			    1 + v_dim1], ldv, &c_b14, &work[work_offset], 
  			    ldwork);
  		}
  
  /*              W := W * T  or  W * T**T */
  
  		igraphdtrmm_("Right", "Upper", trans, "Non-unit", m, k, &c_b14, &t[
  			t_offset], ldt, &work[work_offset], ldwork);
  
  /*              C := C - W * V**T */
  
  		if (*n > *k) {
  
  /*                 C2 := C2 - W * V2**T */
  
  		    i__1 = *n - *k;
  		    igraphdgemm_("No transpose", "Transpose", m, &i__1, k, &c_b25, &
  			    work[work_offset], ldwork, &v[*k + 1 + v_dim1], 
  			    ldv, &c_b14, &c__[(*k + 1) * c_dim1 + 1], ldc);
  		}
  
  /*              W := W * V1**T */
  
  		igraphdtrmm_("Right", "Lower", "Transpose", "Unit", m, k, &c_b14, &
  			v[v_offset], ldv, &work[work_offset], ldwork);
  
  /*              C1 := C1 - W */
  
  		i__1 = *k;
  		for (j = 1; j <= i__1; ++j) {
  		    i__2 = *m;
  		    for (i__ = 1; i__ <= i__2; ++i__) {
  			c__[i__ + j * c_dim1] -= work[i__ + j * work_dim1];
  /* L50: */
  		    }
  /* L60: */
  		}
  	    }
  
  	} else {
  
  /*           Let  V =  ( V1 )   
                         ( V2 )    (last K rows)   
               where  V2  is unit upper triangular. */
  
  	    if (igraphlsame_(side, "L")) {
  
  /*              Form  H * C  or  H**T * C  where  C = ( C1 )   
                                                        ( C2 )   
  
                  W := C**T * V  =  (C1**T * V1 + C2**T * V2)  (stored in WORK)   
  
                  W := C2**T */
  
  		i__1 = *k;
  		for (j = 1; j <= i__1; ++j) {
  		    igraphdcopy_(n, &c__[*m - *k + j + c_dim1], ldc, &work[j * 
  			    work_dim1 + 1], &c__1);
  /* L70: */
  		}
  
  /*              W := W * V2 */
  
  		igraphdtrmm_("Right", "Upper", "No transpose", "Unit", n, k, &c_b14,
  			 &v[*m - *k + 1 + v_dim1], ldv, &work[work_offset], 
  			ldwork);
  		if (*m > *k) {
  
  /*                 W := W + C1**T * V1 */
  
  		    i__1 = *m - *k;
  		    igraphdgemm_("Transpose", "No transpose", n, k, &i__1, &c_b14, &
  			    c__[c_offset], ldc, &v[v_offset], ldv, &c_b14, &
  			    work[work_offset], ldwork);
  		}
  
  /*              W := W * T**T  or  W * T */
  
  		igraphdtrmm_("Right", "Lower", transt, "Non-unit", n, k, &c_b14, &t[
  			t_offset], ldt, &work[work_offset], ldwork);
  
  /*              C := C - V * W**T */
  
  		if (*m > *k) {
  
  /*                 C1 := C1 - V1 * W**T */
  
  		    i__1 = *m - *k;
  		    igraphdgemm_("No transpose", "Transpose", &i__1, n, k, &c_b25, &
  			    v[v_offset], ldv, &work[work_offset], ldwork, &
  			    c_b14, &c__[c_offset], ldc)
  			    ;
  		}
  
  /*              W := W * V2**T */
  
  		igraphdtrmm_("Right", "Upper", "Transpose", "Unit", n, k, &c_b14, &
  			v[*m - *k + 1 + v_dim1], ldv, &work[work_offset], 
  			ldwork);
  
  /*              C2 := C2 - W**T */
  
  		i__1 = *k;
  		for (j = 1; j <= i__1; ++j) {
  		    i__2 = *n;
  		    for (i__ = 1; i__ <= i__2; ++i__) {
  			c__[*m - *k + j + i__ * c_dim1] -= work[i__ + j * 
  				work_dim1];
  /* L80: */
  		    }
  /* L90: */
  		}
  
  	    } else if (igraphlsame_(side, "R")) {
  
  /*              Form  C * H  or  C * H**T  where  C = ( C1  C2 )   
  
                  W := C * V  =  (C1*V1 + C2*V2)  (stored in WORK)   
  
                  W := C2 */
  
  		i__1 = *k;
  		for (j = 1; j <= i__1; ++j) {
  		    igraphdcopy_(m, &c__[(*n - *k + j) * c_dim1 + 1], &c__1, &work[
  			    j * work_dim1 + 1], &c__1);
  /* L100: */
  		}
  
  /*              W := W * V2 */
  
  		igraphdtrmm_("Right", "Upper", "No transpose", "Unit", m, k, &c_b14,
  			 &v[*n - *k + 1 + v_dim1], ldv, &work[work_offset], 
  			ldwork);
  		if (*n > *k) {
  
  /*                 W := W + C1 * V1 */
  
  		    i__1 = *n - *k;
  		    igraphdgemm_("No transpose", "No transpose", m, k, &i__1, &
  			    c_b14, &c__[c_offset], ldc, &v[v_offset], ldv, &
  			    c_b14, &work[work_offset], ldwork);
  		}
  
  /*              W := W * T  or  W * T**T */
  
  		igraphdtrmm_("Right", "Lower", trans, "Non-unit", m, k, &c_b14, &t[
  			t_offset], ldt, &work[work_offset], ldwork);
  
  /*              C := C - W * V**T */
  
  		if (*n > *k) {
  
  /*                 C1 := C1 - W * V1**T */
  
  		    i__1 = *n - *k;
  		    igraphdgemm_("No transpose", "Transpose", m, &i__1, k, &c_b25, &
  			    work[work_offset], ldwork, &v[v_offset], ldv, &
  			    c_b14, &c__[c_offset], ldc)
  			    ;
  		}
  
  /*              W := W * V2**T */
  
  		igraphdtrmm_("Right", "Upper", "Transpose", "Unit", m, k, &c_b14, &
  			v[*n - *k + 1 + v_dim1], ldv, &work[work_offset], 
  			ldwork);
  
  /*              C2 := C2 - W */
  
  		i__1 = *k;
  		for (j = 1; j <= i__1; ++j) {
  		    i__2 = *m;
  		    for (i__ = 1; i__ <= i__2; ++i__) {
  			c__[i__ + (*n - *k + j) * c_dim1] -= work[i__ + j * 
  				work_dim1];
  /* L110: */
  		    }
  /* L120: */
  		}
  	    }
  	}
  
      } else if (igraphlsame_(storev, "R")) {
  
  	if (igraphlsame_(direct, "F")) {
  
  /*           Let  V =  ( V1  V2 )    (V1: first K columns)   
               where  V1  is unit upper triangular. */
  
  	    if (igraphlsame_(side, "L")) {
  
  /*              Form  H * C  or  H**T * C  where  C = ( C1 )   
                                                        ( C2 )   
  
                  W := C**T * V**T  =  (C1**T * V1**T + C2**T * V2**T) (stored in WORK)   
  
                  W := C1**T */
  
  		i__1 = *k;
  		for (j = 1; j <= i__1; ++j) {
  		    igraphdcopy_(n, &c__[j + c_dim1], ldc, &work[j * work_dim1 + 1],
  			     &c__1);
  /* L130: */
  		}
  
  /*              W := W * V1**T */
  
  		igraphdtrmm_("Right", "Upper", "Transpose", "Unit", n, k, &c_b14, &
  			v[v_offset], ldv, &work[work_offset], ldwork);
  		if (*m > *k) {
  
  /*                 W := W + C2**T * V2**T */
  
  		    i__1 = *m - *k;
  		    igraphdgemm_("Transpose", "Transpose", n, k, &i__1, &c_b14, &
  			    c__[*k + 1 + c_dim1], ldc, &v[(*k + 1) * v_dim1 + 
  			    1], ldv, &c_b14, &work[work_offset], ldwork);
  		}
  
  /*              W := W * T**T  or  W * T */
  
  		igraphdtrmm_("Right", "Upper", transt, "Non-unit", n, k, &c_b14, &t[
  			t_offset], ldt, &work[work_offset], ldwork);
  
  /*              C := C - V**T * W**T */
  
  		if (*m > *k) {
  
  /*                 C2 := C2 - V2**T * W**T */
  
  		    i__1 = *m - *k;
  		    igraphdgemm_("Transpose", "Transpose", &i__1, n, k, &c_b25, &v[(
  			    *k + 1) * v_dim1 + 1], ldv, &work[work_offset], 
  			    ldwork, &c_b14, &c__[*k + 1 + c_dim1], ldc);
  		}
  
  /*              W := W * V1 */
  
  		igraphdtrmm_("Right", "Upper", "No transpose", "Unit", n, k, &c_b14,
  			 &v[v_offset], ldv, &work[work_offset], ldwork);
  
  /*              C1 := C1 - W**T */
  
  		i__1 = *k;
  		for (j = 1; j <= i__1; ++j) {
  		    i__2 = *n;
  		    for (i__ = 1; i__ <= i__2; ++i__) {
  			c__[j + i__ * c_dim1] -= work[i__ + j * work_dim1];
  /* L140: */
  		    }
  /* L150: */
  		}
  
  	    } else if (igraphlsame_(side, "R")) {
  
  /*              Form  C * H  or  C * H**T  where  C = ( C1  C2 )   
  
                  W := C * V**T  =  (C1*V1**T + C2*V2**T)  (stored in WORK)   
  
                  W := C1 */
  
  		i__1 = *k;
  		for (j = 1; j <= i__1; ++j) {
  		    igraphdcopy_(m, &c__[j * c_dim1 + 1], &c__1, &work[j * 
  			    work_dim1 + 1], &c__1);
  /* L160: */
  		}
  
  /*              W := W * V1**T */
  
  		igraphdtrmm_("Right", "Upper", "Transpose", "Unit", m, k, &c_b14, &
  			v[v_offset], ldv, &work[work_offset], ldwork);
  		if (*n > *k) {
  
  /*                 W := W + C2 * V2**T */
  
  		    i__1 = *n - *k;
  		    igraphdgemm_("No transpose", "Transpose", m, k, &i__1, &c_b14, &
  			    c__[(*k + 1) * c_dim1 + 1], ldc, &v[(*k + 1) * 
  			    v_dim1 + 1], ldv, &c_b14, &work[work_offset], 
  			    ldwork);
  		}
  
  /*              W := W * T  or  W * T**T */
  
  		igraphdtrmm_("Right", "Upper", trans, "Non-unit", m, k, &c_b14, &t[
  			t_offset], ldt, &work[work_offset], ldwork);
  
  /*              C := C - W * V */
  
  		if (*n > *k) {
  
  /*                 C2 := C2 - W * V2 */
  
  		    i__1 = *n - *k;
  		    igraphdgemm_("No transpose", "No transpose", m, &i__1, k, &
  			    c_b25, &work[work_offset], ldwork, &v[(*k + 1) * 
  			    v_dim1 + 1], ldv, &c_b14, &c__[(*k + 1) * c_dim1 
  			    + 1], ldc);
  		}
  
  /*              W := W * V1 */
  
  		igraphdtrmm_("Right", "Upper", "No transpose", "Unit", m, k, &c_b14,
  			 &v[v_offset], ldv, &work[work_offset], ldwork);
  
  /*              C1 := C1 - W */
  
  		i__1 = *k;
  		for (j = 1; j <= i__1; ++j) {
  		    i__2 = *m;
  		    for (i__ = 1; i__ <= i__2; ++i__) {
  			c__[i__ + j * c_dim1] -= work[i__ + j * work_dim1];
  /* L170: */
  		    }
  /* L180: */
  		}
  
  	    }
  
  	} else {
  
  /*           Let  V =  ( V1  V2 )    (V2: last K columns)   
               where  V2  is unit lower triangular. */
  
  	    if (igraphlsame_(side, "L")) {
  
  /*              Form  H * C  or  H**T * C  where  C = ( C1 )   
                                                        ( C2 )   
  
                  W := C**T * V**T  =  (C1**T * V1**T + C2**T * V2**T) (stored in WORK)   
  
                  W := C2**T */
  
  		i__1 = *k;
  		for (j = 1; j <= i__1; ++j) {
  		    igraphdcopy_(n, &c__[*m - *k + j + c_dim1], ldc, &work[j * 
  			    work_dim1 + 1], &c__1);
  /* L190: */
  		}
  
  /*              W := W * V2**T */
  
  		igraphdtrmm_("Right", "Lower", "Transpose", "Unit", n, k, &c_b14, &
  			v[(*m - *k + 1) * v_dim1 + 1], ldv, &work[work_offset]
  			, ldwork);
  		if (*m > *k) {
  
  /*                 W := W + C1**T * V1**T */
  
  		    i__1 = *m - *k;
  		    igraphdgemm_("Transpose", "Transpose", n, k, &i__1, &c_b14, &
  			    c__[c_offset], ldc, &v[v_offset], ldv, &c_b14, &
  			    work[work_offset], ldwork);
  		}
  
  /*              W := W * T**T  or  W * T */
  
  		igraphdtrmm_("Right", "Lower", transt, "Non-unit", n, k, &c_b14, &t[
  			t_offset], ldt, &work[work_offset], ldwork);
  
  /*              C := C - V**T * W**T */
  
  		if (*m > *k) {
  
  /*                 C1 := C1 - V1**T * W**T */
  
  		    i__1 = *m - *k;
  		    igraphdgemm_("Transpose", "Transpose", &i__1, n, k, &c_b25, &v[
  			    v_offset], ldv, &work[work_offset], ldwork, &
  			    c_b14, &c__[c_offset], ldc);
  		}
  
  /*              W := W * V2 */
  
  		igraphdtrmm_("Right", "Lower", "No transpose", "Unit", n, k, &c_b14,
  			 &v[(*m - *k + 1) * v_dim1 + 1], ldv, &work[
  			work_offset], ldwork);
  
  /*              C2 := C2 - W**T */
  
  		i__1 = *k;
  		for (j = 1; j <= i__1; ++j) {
  		    i__2 = *n;
  		    for (i__ = 1; i__ <= i__2; ++i__) {
  			c__[*m - *k + j + i__ * c_dim1] -= work[i__ + j * 
  				work_dim1];
  /* L200: */
  		    }
  /* L210: */
  		}
  
  	    } else if (igraphlsame_(side, "R")) {
  
  /*              Form  C * H  or  C * H'  where  C = ( C1  C2 )   
  
                  W := C * V**T  =  (C1*V1**T + C2*V2**T)  (stored in WORK)   
  
                  W := C2 */
  
  		i__1 = *k;
  		for (j = 1; j <= i__1; ++j) {
  		    igraphdcopy_(m, &c__[(*n - *k + j) * c_dim1 + 1], &c__1, &work[
  			    j * work_dim1 + 1], &c__1);
  /* L220: */
  		}
  
  /*              W := W * V2**T */
  
  		igraphdtrmm_("Right", "Lower", "Transpose", "Unit", m, k, &c_b14, &
  			v[(*n - *k + 1) * v_dim1 + 1], ldv, &work[work_offset]
  			, ldwork);
  		if (*n > *k) {
  
  /*                 W := W + C1 * V1**T */
  
  		    i__1 = *n - *k;
  		    igraphdgemm_("No transpose", "Transpose", m, k, &i__1, &c_b14, &
  			    c__[c_offset], ldc, &v[v_offset], ldv, &c_b14, &
  			    work[work_offset], ldwork);
  		}
  
  /*              W := W * T  or  W * T**T */
  
  		igraphdtrmm_("Right", "Lower", trans, "Non-unit", m, k, &c_b14, &t[
  			t_offset], ldt, &work[work_offset], ldwork);
  
  /*              C := C - W * V */
  
  		if (*n > *k) {
  
  /*                 C1 := C1 - W * V1 */
  
  		    i__1 = *n - *k;
  		    igraphdgemm_("No transpose", "No transpose", m, &i__1, k, &
  			    c_b25, &work[work_offset], ldwork, &v[v_offset], 
  			    ldv, &c_b14, &c__[c_offset], ldc);
  		}
  
  /*              W := W * V2 */
  
  		igraphdtrmm_("Right", "Lower", "No transpose", "Unit", m, k, &c_b14,
  			 &v[(*n - *k + 1) * v_dim1 + 1], ldv, &work[
  			work_offset], ldwork);
  
  /*              C1 := C1 - W */
  
  		i__1 = *k;
  		for (j = 1; j <= i__1; ++j) {
  		    i__2 = *m;
  		    for (i__ = 1; i__ <= i__2; ++i__) {
  			c__[i__ + (*n - *k + j) * c_dim1] -= work[i__ + j * 
  				work_dim1];
  /* L230: */
  		    }
  /* L240: */
  		}
  
  	    }
  
  	}
      }
  
      return 0;
  
  /*     End of DLARFB */
  
  } /* igraphdlarfb_ */
  
  