docs: def stl(A, b):
      r"""Shortcut to ``solve_triangular(A, b, lower=True, check_finite=False)``.
  
      Solve linear systems :math:`\mathrm A \mathbf x = \mathbf b` when
      :math:`\mathrm A` is a lower-triangular matrix.
  
      Args:
          A (array_like): A lower-triangular matrix.
          b (array_like): Ordinate values.
  
      Returns:
          :class:`numpy.ndarray`: Solution ``x``.
  
      See Also
      --------
      scipy.linalg.solve_triangular: Solve triangular linear equations.
      """
      from scipy.linalg import solve_triangular
  
      A = asarray(A, float)
      b = asarray(b, float)
      return solve_triangular(A, b, lower=True, check_finite=False)