code: def bei(ctx, n, z, **kwargs):
      n = ctx.convert(n)
      z = ctx.convert(z)
  
      # http://functions.wolfram.com/Bessel-TypeFunctions/KelvinBei2/26/01/02/0001/
      def h(n):
          r = -((z / 4) ** 4)
          cos, sin = ctx.cospi_sinpi(0.75 * n)
          T1 = (
              [cos, z / 2],
              [1, n + 2],
              [],
              [n + 2],
              [],
              [1.5, 0.5 * (n + 3), 0.5 * n + 1],
              r,
          )
          T2 = (
              [sin, z / 2],
              [1, n],
              [],
              [n + 1],
              [],
              [0.5, 0.5 * (n + 1), 0.5 * n + 1],
              r,
          )
          return T1, T2
  
      return ctx.hypercomb(h, [n], **kwargs)
  
imports: from .functions import defun, defun_wrapped
label_desc: Use image node_id 20 for calling a global function with example usage: bei(ctx, n, z) and returns: ctx, T1,  T2