text: #ifndef DYNEARTHSOL3D_RHEOLOGY_HPP
  #define DYNEARTHSOL3D_RHEOLOGY_HPP
  
  void update_stress(const Variables& var, tensor_t& stress, double_vec& stressyy,
                     double_vec& dpressure, tensor_t& strain, double_vec& plstrain,
                     double_vec& delta_plstrain, tensor_t& strain_rate);
  
  #endif
  