docs: def _state_removal_remove(self, k):
          """
          State Removal Remove operation
          l_transitions[i,i] += l_transitions[i,k] . star(l_transitions[k,k]) . l_transitions[k,i]
          l_transitions[j,j] += l_transitions[j,k] . star(l_transitions[k,k]) . l_transitions[k,j]
          l_transitions[i,j] += l_transitions[i,k] . star(l_transitions[k,k]) . l_transitions[k,j]
          l_transitions[j,i] += l_transitions[j,k] . star(l_transitions[k,k]) . l_transitions[k,i]
          Args:
              k (int): The node that will be removed
          Returns:
              None
          """
          for state_i in self.mma.states:
              for state_j in self.mma.states:
                  if self.l_transitions[state_i.stateid, k] != self.empty:
                      l_ik = self.l_transitions[state_i.stateid, k]
                  else:
                      l_ik = ""
                  if self.l_transitions[state_j.stateid, k] != self.empty:
                      l_jk = self.l_transitions[state_j.stateid, k]
                  else:
                      l_jk = ""
                  if self.l_transitions[k, state_i.stateid] != self.empty:
                      l_ki = self.l_transitions[k, state_i.stateid]
                  else:
                      l_ki = ""
                  if self.l_transitions[k, state_j.stateid] != self.empty:
                      l_kj = self.l_transitions[k, state_j.stateid]
                  else:
                      l_kj = ""
  
                  if self.l_transitions[state_i.stateid, state_i.stateid] != self.empty:
                      self.l_transitions[state_i.stateid, state_i.stateid] += l_ik + \
                          self.star(self.l_transitions[k, k]) + l_ki
                  else:
                      self.l_transitions[state_i.stateid, state_i.stateid] = l_ik + \
                          self.star(self.l_transitions[k, k]) + l_ki
  
                  if self.l_transitions[state_j.stateid, state_j.stateid] != self.empty:
                      self.l_transitions[state_j.stateid, state_j.stateid] += l_jk + \
                          self.star(self.l_transitions[k, k]) + l_kj
                  else:
                      self.l_transitions[state_j.stateid, state_j.stateid] = l_jk + \
                          self.star(self.l_transitions[k, k]) + l_kj
  
                  if self.l_transitions[state_i.stateid, state_j.stateid] != self.empty:
                      self.l_transitions[state_i.stateid, state_j.stateid] += l_ik + \
                          self.star(self.l_transitions[k, k]) + l_kj
                  else:
                      self.l_transitions[state_i.stateid, state_j.stateid] = l_ik + \
                          self.star(self.l_transitions[k, k]) + l_kj
  
                  if self.l_transitions[state_j.stateid, state_i.stateid] != self.empty:
                      self.l_transitions[state_j.stateid, state_i.stateid] += l_jk + \
                          self.star(self.l_transitions[k, k]) + l_ki
                  else:
                      self.l_transitions[state_j.stateid, state_i.stateid] = l_jk + \
                          self.star(self.l_transitions[k, k]) + l_ki