[Beam]
  free  M[:]
  free  V[:]
  free  dx
  free  th[:]
  free  w[:]
  fixed EI
  fixed L
  fixed M_tip
  fixed V_tip
  fixed q[:]
  fixed th_base
  fixed w_base
  cons (definition of dx)  L = 3·dx
  cons (boundary_conditions)  V[3] ≥ V_tip
  cons (boundary_conditions)  M[3] ≥ M_tip
  cons (boundary_conditions)  th[0] ≥ th_base
  cons (boundary_conditions)  w[0] ≥ w_base
  cons (shear integration)  V[0] ≥ V[1] + 0.5·dx·(q[0] + q[1])
  cons (shear integration)  V[1] ≥ V[2] + 0.5·dx·(q[1] + q[2])
  cons (shear integration)  V[2] ≥ V[3] + 0.5·dx·(q[2] + q[3])
  cons (moment integration)  M[0] ≥ M[1] + 0.5·dx·(V[0] + V[1])
  cons (moment integration)  M[1] ≥ M[2] + 0.5·dx·(V[1] + V[2])
  cons (moment integration)  M[2] ≥ M[3] + 0.5·dx·(V[2] + V[3])
  cons (theta integration)  th[1] ≥ th[0] + 0.5·dx·(M[1] + M[0])/EI
  cons (theta integration)  th[2] ≥ th[1] + 0.5·dx·(M[2] + M[1])/EI
  cons (theta integration)  th[3] ≥ th[2] + 0.5·dx·(M[3] + M[2])/EI
  cons (displacement integration)  w[1] ≥ w[0] + 0.5·dx·(th[1] + th[0])
  cons (displacement integration)  w[2] ≥ w[1] + 0.5·dx·(th[2] + th[1])
  cons (displacement integration)  w[3] ≥ w[2] + 0.5·dx·(th[3] + th[2])
