591    SUBROUTINE bgrat(a, b, x, y, w, eps, ierr)  subroutine
598       REAL(dp), INTENT(IN)                               :: a, b, x, y  local
599       REAL(dp), INTENT(INOUT)                            :: w  local
600       REAL(dp), INTENT(IN)                               :: eps
601       INTEGER, INTENT(OUT)                               :: ierr
603       REAL(dp), PARAMETER                                :: half = 0.5e0_dp, one = 1.e0_dp, &
604                                                             quarter = 0.25e0_dp, zero = 0.e0_dp
606       INTEGER                                            :: i, n  local
607       REAL(dp)                                           :: bm1, bp2n, c(30), cn, coef, d(30), dj, &
608                                                             j, l, lnx, n2, nu, q, r, s, sum, t, &
609                                                             t2, tol, u, v, z  local