...

  'Initialisierung
  SA = a - 2 * ea
  SB = b - 2 * eb
  Nd = Exp(pi * Tan(phi)) * Tan(pi / 4 + phi / 2) ^ 2
  Nc = (Nd - 1) / Tan(phi)
  Nb = (Nd - 1) * Tan(phi)
  vb = 1 - 0.3 * SB / SA
  vd = 1 + SB * Sin(phi) / SA
  vc = (vd * Nd - 1) / (Nd - 1)
  V1 = a * b * 100
  H1 = V1 * Tan(delta)
  
  'Iteration
  ...
    i = i + 1
    V2 = V1
    Kd = (1 - ((0.7 * H1) / (V1 + (SA * SB * c / Tan(phi))))) ^ 3
    Kc = Kd - ((1 - Kd) / (Nd - 1))
    Kb = (1 - (H1 / (V1 + (SA * SB * c / Tan(phi))))) ^ 3
    V1 = SA * SB * (c * Nc * vc * Kc + gamma1 * d * Nd * Kd * vd + gamma2 * SB * vb * Nb * Kb)
    H1 = V1 * Tan(delta)
  ...