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     .. Array Arguments ..
     ..
  Purpose
  =======
  PSLAPDCT counts the number of negative eigenvalues of (T - SIGMA I).
  This implementation of the Sturm Sequence loop has conditionals in
  the innermost loop to avoid overflow and determine the sign of a
  floating point number. PSLAPDCT will be referred to as the "paranoid"
  implementation of the Sturm Sequence loop.
  This is a SCALAPACK internal procedure and arguments are not checked
  for unreasonable values.
  Arguments
  =========
  SIGMA   (input) REAL
          The shift. PSLAPDCT finds the number of eigenvalues of T less
          than or equal to SIGMA.
  N       (input) INTEGER
          The order of the tridiagonal matrix T. N >= 1.
  D       (input) REAL array, dimension (2*N - 1)
          Contains the diagonals and the squares of the off-diagonal
          elements of the tridiagonal matrix T. These elements are
          assumed to be interleaved in memory for better cache
          performance. The diagonal entries of T are in the entries
          D(1),D(3),...,D(2*N-1), while the squares of the off-diagonal
          entries are D(2),D(4),...,D(2*N-2). To avoid overflow, the
          matrix must be scaled so that its largest entry is no greater
          than overflow**(1/2) * underflow**(1/4) in absolute value,
          and for greatest accuracy, it should not be much smaller
          than that.
  PIVMIN  (input) REAL
          The minimum absolute of a "pivot" in this "paranoid"
          implementation of the Sturm sequence loop. This must be at
          least max_j |e(j)^2| *safe_min, and at least safe_min, where
          safe_min is at least the smallest number that can divide 1.0
          without overflow.
  COUNT   (output) INTEGER
          The count of the number of eigenvalues of T less than or
          equal to SIGMA.
  =====================================================================
     .. Intrinsic Functions ..