Model is underconstrained.
The following variables couldn't be defined:
 * V in component membrane
 * i_K in component potassium_current
 * i_Ca in component calcium_current
 * i_s in component slow_current
 * m_infinity in component calcium_current_m_gate
 * n_infinity in component potassium_current_n_gate
 * s_infinity in component slow_current_s_gate
 * d/dt V in component membrane
 * d/dt n in component potassium_current_n_gate
 * d/dt s in component slow_current_s_gate