//Created by libAntimony v2.4

// Warnings from automatic translation:
//    Unable to use the formula "pi * preplength * power(radius, 2)" to set the assignment rule for volume:  The variable 'volume' is the type Unit Definition, and may not have an assignment rule associated with it.

model viswanathan_1999_epi__environment(time_)

  // Variable initializations:
  time_ = ;
end

model viswanathan_1999_epi__membrane(V, R, T, F, time_, i_Na, i_Ca_L, i_Ca_T, i_Kr, i_Ks, i_K_ATP, i_to, i_K1, i_Kp, i_p_Ca, i_Na_b, i_Ca_b, i_NaK, i_NaCa, i_ns_Ca, dVdt)

  // Assignment Rules:
  I_st := piecewise( stim_amplitude , (( geq(time_, stim_start)) && (time_ <= stim_end) && ((time_ - stim_start) - floor((time_ - stim_start) / stim_period) * stim_period <= stim_duration )), 0 );
  dVdt := -(i_Na + i_Ca_L + i_Ca_T + i_Kr + i_Ks + i_K_ATP + i_to + i_K1 + i_Kp + i_p_Ca + i_Na_b + i_Ca_b + i_NaK + i_NaCa + i_ns_Ca + I_st);

  // Rate Rules:
  V' = dVdt;

  // Variable initializations:
  V = -88.5004;
  R = 8314;
  T = 310;
  F = 96485;
  time_ = ;
  i_Na = ;
  i_Ca_L = ;
  i_Ca_T = ;
  i_Kr = ;
  i_Ks = ;
  i_K_ATP = ;
  i_to = ;
  i_K1 = ;
  i_Kp = ;
  i_p_Ca = ;
  i_Na_b = ;
  i_Ca_b = ;
  i_NaK = ;
  i_NaCa = ;
  i_ns_Ca = ;
  stim_start = 100;
  stim_end = 99999000;
  stim_period = 1000;
  stim_duration = 2;
  stim_amplitude = -25.5;
end

model viswanathan_1999_epi__fast_sodium_current_m_gate(m, V, time_)

  // Assignment Rules:
  alpha_m := piecewise( (0.32 * E0_m) / (1 - exp(-(0.1) * E0_m)) , geq(abs(E0_m), delta_m) , 3.2 );
  beta_m := 0.08 * exp(- V / 11);
  E0_m := V + 47.13;

  // Rate Rules:
  m' = alpha_m * (1 - m) - beta_m * m;

  // Variable initializations:
  m = 0.0008601;
  V = ;
  delta_m = 1e-5;
  time_ = ;
end

model viswanathan_1999_epi__fast_sodium_current_h_gate(h, V, time_)

  // Assignment Rules:
  alpha_h := piecewise( 0.135 * exp((80 + V) / -(6.8)) , V < -(40) , 0 );
  beta_h := piecewise( 3.56 * exp(0.079 * V) + 310000 * exp(0.35 * V) , V < -(40) , 1 / (0.13 * (1 + exp((V + 10.66) / -(11.1)))) );

  // Rate Rules:
  h' = alpha_h * (1 - h) - beta_h * h;

  // Variable initializations:
  h = 0.992806;
  V = ;
  time_ = ;
end

model viswanathan_1999_epi__fast_sodium_current_j_gate(j, V, time_)

  // Assignment Rules:
  alpha_j := piecewise( (-(127140 * exp(0.2444 * V) + 3.474E-5 * exp(-(0.04391) * V)) * (V + 37.78)) / (1 + exp(0.311 * (V + 79.23))) , V < -(40) , 0 );
  beta_j := piecewise( (0.1212 * exp(-(0.01052) * V)) / (1 + exp(-(0.1378) * (V + 40.14))) , V < -(40) , (0.3 * exp(-(2.535E-7) * V)) / (1 + exp(-(0.1) * (V + 32))) );

  // Rate Rules:
  j' = alpha_j * (1 - j) - beta_j * j;

  // Variable initializations:
  j = 0.99511469;
  V = ;
  time_ = ;
end

model viswanathan_1999_epi__fast_sodium_current(i_Na, E_Na, time_, V, R, F, T, Nai, Nao, m, h, j)

  // Sub-modules, and any changes to those submodules:
  fast_sodium_current_m_gate: viswanathan_1999_epi__fast_sodium_current_m_gate(m, V, time_);
  fast_sodium_current_h_gate: viswanathan_1999_epi__fast_sodium_current_h_gate(h, V, time_);
  fast_sodium_current_j_gate: viswanathan_1999_epi__fast_sodium_current_j_gate(j, V, time_);

  // Assignment Rules:
  i_Na := g_Na * power(m, 3) * h * j * (V - E_Na);
  E_Na := ((R * T) / F) * ln(Nao / Nai);

  // Variable initializations:
  g_Na = 16;
  R = ;
  F = ;
  T = ;
  Nai = ;
  Nao = ;
end

model viswanathan_1999_epi__L_type_Ca_channel_d_gate(d, V, time_)

  // Assignment Rules:
  alpha_d := d_infinity / tau_d;
  beta_d := (1 - d_infinity) / tau_d;
  d_infinity := 1 / (1 + exp(- E0_d / 6.24));
  tau_d := piecewise( 1 / (0.035 * 6.24) , abs(E0_d) < 1E-5 , (d_infinity * (1 - exp(- E0_d / 6.24))) / (0.035 * E0_d) );
  E0_d := V + 10;

  // Rate Rules:
  d' = alpha_d * (1 - d) - beta_d * d;

  // Variable initializations:
  d = 3.538268e-6;
  V = ;
  time_ = ;
end

model viswanathan_1999_epi__L_type_Ca_channel_f_gate(f, V, time_)

  // Assignment Rules:
  alpha_f := f_infinity / tau_f;
  beta_f := (1 - f_infinity) / tau_f;
  f_infinity := 1 / (1 + exp((V + 32) / 8)) + 0.6 / (1 + exp((50 - V) / 20));
  tau_f := 1 / (0.0197 * exp(-power(0.0337 * (V + 10), 2)) + 0.02);

  // Rate Rules:
  f' = alpha_f * (1 - f) - beta_f * f;

  // Variable initializations:
  f = 0.995259;
  V = ;
  time_ = ;
end

model viswanathan_1999_epi__L_type_Ca_channel_f_Ca_gate(f_Ca, V, Cai)

  // Assignment Rules:
  f_Ca := 1 / (1 + Cai / Km_Ca);

  // Variable initializations:
  Km_Ca = 0.0006;
  V = ;
  Cai = ;
end

model viswanathan_1999_epi__L_type_Ca_channel(i_Ca_L, i_CaCa, i_CaK, i_CaNa, gamma_Nai, gamma_Nao, gamma_Ki, gamma_Ko, time_, V, Cai, R, T, F, Cao, Nao, Ko, Nai, Ki, d, f, f_Ca)

  // Sub-modules, and any changes to those submodules:
  L_type_Ca_channel_d_gate: viswanathan_1999_epi__L_type_Ca_channel_d_gate(d, V, time_);
  L_type_Ca_channel_f_gate: viswanathan_1999_epi__L_type_Ca_channel_f_gate(f, V, time_);
  L_type_Ca_channel_f_Ca_gate: viswanathan_1999_epi__L_type_Ca_channel_f_Ca_gate(f_Ca, V, Cai);

  // Assignment Rules:
  i_Ca_L := i_CaCa + i_CaK + i_CaNa;
  i_CaCa := d * f * f_Ca * I_CaCa;
  i_CaK := d * f * f_Ca * I_CaK;
  i_CaNa := d * f * f_Ca * I_CaNa;
  I_CaCa := (((P_Ca * power(2, 2) * V * power(F, 2)) / (R * T)) * (gamma_Cai * Cai * exp((2 * V * F) / (R * T)) - gamma_Cao * Cao)) / (exp((2 * V * F) / (R * T)) - 1);
  I_CaK := (((P_K * power(1, 2) * V * power(F, 2)) / (R * T)) * (gamma_Ki * Ki * exp((1 * V * F) / (R * T)) - gamma_Ko * Ko)) / (exp((1 * V * F) / (R * T)) - 1);
  I_CaNa := (((P_Na * power(1, 2) * V * power(F, 2)) / (R * T)) * (gamma_Nai * Nai * exp((1 * V * F) / (R * T)) - gamma_Nao * Nao)) / (exp((1 * V * F) / (R * T)) - 1);

  // Variable initializations:
  gamma_Nai = 0.75;
  gamma_Nao = 0.75;
  gamma_Ki = 0.75;
  gamma_Ko = 0.75;
  P_Ca = 0.00054;
  P_Na = 6.75e-7;
  P_K = 1.93e-7;
  gamma_Cai = 1;
  gamma_Cao = 0.341;
  R = ;
  T = ;
  F = ;
  Cao = ;
  Nao = ;
  Ko = ;
  Nai = ;
  Ki = ;
end

model viswanathan_1999_epi__T_type_Ca_channel_b_gate(b, V, time_)

  // Assignment Rules:
  b_inf := 1 / (1 + exp(-(V + 14) / 10.8));
  tau_b := 3.7 + 6.1 / (1 + exp((V + 25) / 4.5));

  // Rate Rules:
  b' = (b_inf - b) / tau_b;

  // Variable initializations:
  b = 0.0010301;
  V = ;
  time_ = ;
end

model viswanathan_1999_epi__T_type_Ca_channel_g_gate(g, V, time_)

  // Assignment Rules:
  g_inf := 1 / (1 + exp((V + 60) / 5.6));
  tau_g := piecewise( -(0.875) * V + 12 , V <= 0 , 12 );

  // Rate Rules:
  g' = (g_inf - g) / tau_g;

  // Variable initializations:
  g = 0.9341828;
  V = ;
  time_ = ;
end

model viswanathan_1999_epi__T_type_Ca_channel(i_Ca_T, E_Ca, time_, V, b, g)

  // Sub-modules, and any changes to those submodules:
  T_type_Ca_channel_b_gate: viswanathan_1999_epi__T_type_Ca_channel_b_gate(b, V, time_);
  T_type_Ca_channel_g_gate: viswanathan_1999_epi__T_type_Ca_channel_g_gate(g, V, time_);

  // Assignment Rules:
  i_Ca_T := g_CaT * b * b * g * (V - E_Ca);

  // Variable initializations:
  g_CaT = 0.05;
  E_Ca = ;
end

model viswanathan_1999_epi__rapid_delayed_rectifier_potassium_current_xr_gate(xr, V, time_)

  // Assignment Rules:
  xr_infinity := 1 / (1 + exp(-(V + 21.5) / 7.5));
  tau_xr := 1 / ((0.00138 * (V + 14.2)) / (1 - exp(-(0.123) * (V + 14.2))) + (0.00061 * (V + 38.9)) / (exp(0.145 * (V + 38.9)) - 1));

  // Rate Rules:
  xr' = (xr_infinity - xr) / tau_xr;

  // Variable initializations:
  xr = 0.0007500578;
  V = ;
  time_ = ;
end

model viswanathan_1999_epi__rapid_delayed_rectifier_potassium_current(i_Kr, E_K, time_, V, Ko, xr)

  // Sub-modules, and any changes to those submodules:
  rapid_delayed_rectifier_potassium_current_xr_gate: viswanathan_1999_epi__rapid_delayed_rectifier_potassium_current_xr_gate(xr, V, time_);

  // Assignment Rules:
  i_Kr := g_Kr * xr * Rect * (V - E_K);
  g_Kr := 0.02614 * root(Ko / 5.4);
  Rect := 1 / (1 + exp((V + 9) / 22.4));

  // Variable initializations:
  E_K = ;
  Ko = ;
end

model viswanathan_1999_epi__slow_delayed_rectifier_potassium_current_xs1_gate(xs1, V, time_)

  // Assignment Rules:
  xs1_infinity := 1 / (1 + exp(-(V - 1.5) / 16.7));
  tau_xs1 := 1 / ((7.19E-5 * (V + 30)) / (1 - exp(-(0.148) * (V + 30))) + (0.000131 * (V + 30)) / (exp(0.0687 * (V + 30)) - 1));

  // Rate Rules:
  xs1' = (xs1_infinity - xs1) / tau_xs1;

  // Variable initializations:
  xs1 = 0.0421517;
  V = ;
  time_ = ;
end

model viswanathan_1999_epi__slow_delayed_rectifier_potassium_current_xs2_gate(xs2, V, time_)

  // Assignment Rules:
  xs2_infinity := 1 / (1 + exp(-(V - 1.5) / 16.7));
  tau_xs2 := 4 / ((7.19E-5 * (V + 30)) / (1 - exp(-(0.148) * (V + 30))) + (0.000131 * (V + 30)) / (exp(0.0687 * (V + 30)) - 1));

  // Rate Rules:
  xs2' = (xs2_infinity - xs2) / tau_xs2;

  // Variable initializations:
  xs2 = 0.08866;
  V = ;
  time_ = ;
end

model viswanathan_1999_epi__slow_delayed_rectifier_potassium_current(i_Ks, time_, V, R, T, F, Ko, Ki, Nao, Nai, Cai, xs1, xs2)

  // Sub-modules, and any changes to those submodules:
  slow_delayed_rectifier_potassium_current_xs1_gate: viswanathan_1999_epi__slow_delayed_rectifier_potassium_current_xs1_gate(xs1, V, time_);
  slow_delayed_rectifier_potassium_current_xs2_gate: viswanathan_1999_epi__slow_delayed_rectifier_potassium_current_xs2_gate(xs2, V, time_);

  // Assignment Rules:
  i_Ks := g_Ks * xs1 * xs2 * (V - E_Ks);
  g_Ks := 0.289 * (1 + 0.6 / (1 + power(3.8E-5 / Cai, 1.4)));
  E_Ks := ((R * T) / F) * ln((Ko + PNaK * Nao) / (Ki + PNaK * Nai));

  // Variable initializations:
  PNaK = 0.01833;
  R = ;
  T = ;
  F = ;
  Ko = ;
  Ki = ;
  Nao = ;
  Nai = ;
  Cai = ;
end

model viswanathan_1999_epi__time_independent_potassium_current_K1_gate(K1_infinity, V, E_K)

  // Assignment Rules:
  K1_infinity := alpha_K1 / (alpha_K1 + beta_K1);
  alpha_K1 := 1.02 / (1 + exp(0.2385 * ((V - E_K) - 59.215)));
  beta_K1 := (1 * (0.49124 * exp(0.08032 * ((V - E_K) + 5.476)) + exp(0.06175 * ((V - E_K) - 594.31)))) / (1 + exp(-(0.5143) * ((V - E_K) + 4.753)));

  // Variable initializations:
  V = ;
  E_K = ;
end

model viswanathan_1999_epi__time_independent_potassium_current(i_K1, E_K, V, Ko, Ki, R, T, F, K1_infinity)

  // Sub-modules, and any changes to those submodules:
  time_independent_potassium_current_K1_gate: viswanathan_1999_epi__time_independent_potassium_current_K1_gate(K1_infinity, V, E_K);

  // Assignment Rules:
  i_K1 := g_K1 * K1_infinity * (V - E_K);
  E_K := ((R * T) / F) * ln(Ko / Ki);
  g_K1 := 0.75 * root(Ko / 5.4);

  // Variable initializations:
  Ko = ;
  Ki = ;
  R = ;
  T = ;
  F = ;
end

model viswanathan_1999_epi__plateau_potassium_current(i_Kp, V, E_K)

  // Assignment Rules:
  i_Kp := g_Kp * Kp * (V - E_K);
  Kp := 1 / (1 + exp((7.488 - V) / 5.98));

  // Variable initializations:
  g_Kp = 0.00552;
  V = ;
  E_K = ;
end

model viswanathan_1999_epi__ATP_sensitive_potassium_current(i_K_ATP, V, Ko, E_K)

  // Assignment Rules:
  i_K_ATP := GKbaraATP * (V - E_K);
  g_K_ATP := 0.000193 / nicholsarea;
  pATP := 1 / (1 + power(ATPi / kATP, hATP));
  GKbaraATP := g_K_ATP * pATP * power(Ko / 4, nATP);

  // Variable initializations:
  nATP = 0.24;
  nicholsarea = 5e-5;
  ATPi = 3;
  hATP = 2;
  kATP = 0.00025;
  V = ;
  Ko = ;
  E_K = ;
end

model viswanathan_1999_epi__transient_outward_current_zdv_gate(zdv, V, time_)

  // Assignment Rules:
  alpha_zdv := (10 * exp((V - 40) / 25)) / (1 + exp((V - 40) / 25));
  beta_zdv := (10 * exp(-(V + 90) / 25)) / (1 + exp(-(V + 90) / 25));
  tau_zdv := 1 / (alpha_zdv + beta_zdv);
  zdv_ss := alpha_zdv / (alpha_zdv + beta_zdv);

  // Rate Rules:
  zdv' = (zdv_ss - zdv) / tau_zdv;

  // Variable initializations:
  zdv = 0.01198974;
  V = ;
  time_ = ;
end

model viswanathan_1999_epi__transient_outward_current_ydv_gate(ydv, V, time_)

  // Assignment Rules:
  alpha_ydv := 0.015 / (1 + exp((V + 60) / 5));
  beta_ydv := (0.1 * exp((V + 25) / 5)) / (1 + exp((V + 25) / 5));
  tau_ydv := 1 / (alpha_ydv + beta_ydv);
  ydv_ss := alpha_ydv / (alpha_ydv + beta_ydv);

  // Rate Rules:
  ydv' = (ydv_ss - ydv) / tau_ydv;

  // Variable initializations:
  ydv = 0.97497;
  V = ;
  time_ = ;
end

model viswanathan_1999_epi__transient_outward_current(i_to, E_K, V, time_, zdv, ydv)

  // Sub-modules, and any changes to those submodules:
  transient_outward_current_zdv_gate: viswanathan_1999_epi__transient_outward_current_zdv_gate(zdv, V, time_);
  transient_outward_current_ydv_gate: viswanathan_1999_epi__transient_outward_current_ydv_gate(ydv, V, time_);

  // Assignment Rules:
  i_to := g_to * power(zdv, 3) * ydv * rvdv * (V - E_K);
  g_to := 0 * 0.5;
  rvdv := exp(V / 100);

  // Variable initializations:
  E_K = ;
end

model viswanathan_1999_epi__sarcolemmal_calcium_pump(i_p_Ca, Cai)

  // Assignment Rules:
  i_p_Ca := (I_pCa * Cai) / (K_mpCa + Cai);

  // Variable initializations:
  K_mpCa = 0.0005;
  I_pCa = 1.15;
  Cai = ;
end

model viswanathan_1999_epi__sodium_background_current(i_Na_b, V, E_Na)

  // Assignment Rules:
  i_Na_b := g_Nab * (V - E_Na);

  // Variable initializations:
  g_Nab = 0.004;
  V = ;
  E_Na = ;
end

model viswanathan_1999_epi__calcium_background_current(i_Ca_b, E_Ca, V, R, T, F, Cai, Cao)

  // Assignment Rules:
  i_Ca_b := g_Cab * (V - E_Ca);
  E_Ca := ((R * T) / (2 * F)) * ln(Cao / Cai);

  // Variable initializations:
  g_Cab = 0.003016;
  V = ;
  R = ;
  T = ;
  F = ;
  Cai = ;
  Cao = ;
end

model viswanathan_1999_epi__sodium_potassium_pump(i_NaK, V, R, T, F, Nai, Nao, Ko)

  // Assignment Rules:
  i_NaK := (((I_NaK * f_NaK * 1) / (1 + power(K_mNai / Nai, 2))) * Ko) / (Ko + K_mKo);
  f_NaK := 1 / (1 + 0.1245 * exp((-(0.1) * V * F) / (R * T)) + 0.0365 * sigma * exp((- V * F) / (R * T)));
  sigma := (1 / 7) * (exp(Nao / 67.3) - 1);

  // Variable initializations:
  I_NaK = 2;
  K_mNai = 10;
  K_mKo = 1.5;
  V = ;
  R = ;
  T = ;
  F = ;
  Nai = ;
  Nao = ;
  Ko = ;
end

model viswanathan_1999_epi__non_specific_calcium_activated_current(i_ns_Ca, i_ns_Na, i_ns_K, gamma_Nai, gamma_Nao, gamma_Ki, gamma_Ko, R, T, F, Cao, Nao, Ko, Nai, Ki, time_, Cai, V)

  // Assignment Rules:
  i_ns_Ca := i_ns_Na + i_ns_K;
  i_ns_Na := (I_ns_Na * 1) / (1 + power(K_m_ns_Ca / Cai, 3));
  i_ns_K := (I_ns_K * 1) / (1 + power(K_m_ns_Ca / Cai, 3));
  P_ns_Ca := 0 * 1.75E-7;
  I_ns_Na := (((P_ns_Ca * power(1, 2) * V * power(F, 2)) / (R * T)) * (gamma_Nai * Nai * exp((1 * V * F) / (R * T)) - gamma_Nao * Nao)) / (exp((1 * V * F) / (R * T)) - 1);
  I_ns_K := (((P_ns_Ca * power(1, 2) * V * power(F, 2)) / (R * T)) * (gamma_Ki * Ki * exp((1 * V * F) / (R * T)) - gamma_Ko * Ko)) / (exp((1 * V * F) / (R * T)) - 1);

  // Variable initializations:
  gamma_Nai = ;
  gamma_Nao = ;
  gamma_Ki = ;
  gamma_Ko = ;
  R = ;
  T = ;
  F = ;
  Cao = ;
  Nao = ;
  Ko = ;
  Nai = ;
  Ki = ;
  K_m_ns_Ca = 0.0012;
  time_ = ;
  Cai = ;
  V = ;
end

model viswanathan_1999_epi__Na_Ca_exchanger(i_NaCa, V, R, T, F, Nai, Nao, Cai, Cao, n_NaCa)

  // Assignment Rules:
  i_NaCa := (K_NaCa * (exp((gamma * (n_NaCa - 2) * V * F) / (R * T)) * power(Nai, n_NaCa) * Cao - exp(((gamma - 1) * (n_NaCa - 2) * V * F) / (R * T)) * power(Nao, n_NaCa) * Cai)) / ((1 + d_NaCa * (Cai * power(Nao, n_NaCa) + Cao * power(Nai, n_NaCa))) * (1 + Cai / 0.0069));

  // Variable initializations:
  V = ;
  R = ;
  T = ;
  F = ;
  Nai = ;
  Nao = ;
  Cai = ;
  Cao = ;
  n_NaCa = 3;
  K_NaCa = 0.002;
  d_NaCa = 0.001;
  gamma = 0.5;
end

model viswanathan_1999_epi__calcium_dynamics(i_rel, i_up, i_leak, i_tr, time_, F, Cai, Cao, Ca_JSR, Ca_NSR, V_myo, A_cap, i_NaCa, i_CaCa, i_p_Ca, i_Ca_b, i_Ca_T, dVdt)

  // Assignment Rules:
  i_rel := G_rel * (Ca_JSR - Cai);
  i_up := (I_up * Cai) / (Cai + K_mup);
  i_leak := K_leak * Ca_NSR;
  i_tr := (Ca_NSR - Ca_JSR) / tau_tr;
  G_rel := piecewise( ((G_rel_max * (Cainfluxtrack - delta_Ca_ith)) / ((K_mrel + Cainfluxtrack) - delta_Ca_ith)) * (1 - APtrack2) * APtrack2 , Cainfluxtrack > delta_Ca_ith , G_rel_overload * (1 - OVRLDtrack2) * OVRLDtrack2 , ( Cainfluxtrack <= delta_Ca_ith) && (OVRLDtrack2 > 0 ), 0 );
  K_leak := I_up / Ca_NSR_max;
  V_JSR := (0.0048 / 0.68) * V_myo;
  V_NSR := (0.0552 / 0.68) * V_myo;

  // Rate Rules:
  Cai' = (0.001 / (1 + (CMDN_max * K_mCMDN) / power(K_mCMDN + Cai, 2) + (Tn_max * K_mTn) / power(K_mTn + Cai, 2))) * ((-(1) * A_cap * (((i_CaCa + i_Ca_T) - i_NaCa) + i_p_Ca + i_Ca_b)) / (2 * V_myo * F) + (i_rel * V_JSR) / V_myo + ((i_leak - i_up) * V_NSR) / V_myo);
  Ca_JSR' = (0.001 / (1 + (CSQN_max * K_mCSQN) / power(K_mCSQN + Ca_JSR, 2))) * (i_tr - i_rel);
  Ca_NSR' = 0.001 * (((- i_tr * V_JSR) / V_NSR - i_leak) + i_up);
  APtrack' = piecewise( 100 * (1 - APtrack) - 0.5 * APtrack , dVdt > 150 , -(0.5) * APtrack );
  APtrack2' = piecewise( 100 * (1 - APtrack2) - 0.5 * APtrack2 , ( APtrack < 0.2) && (APtrack > 0.18 ), -(0.5) * APtrack2 );
  APtrack3' = piecewise( 100 * (1 - APtrack3) - 0.5 * APtrack3 , ( APtrack < 0.2) && (APtrack > 0.18 ), -(0.01) * APtrack3 );
  Cainfluxtrack' = piecewise( (-(1) * A_cap * (((i_CaCa + i_Ca_T) - i_NaCa) + i_p_Ca + i_Ca_b)) / (2 * V_myo * F) , APtrack > 0.2 , 0 , ( APtrack2 > 0.01) && (APtrack <= 0.2 ), -(0.5) * Cainfluxtrack );
  OVRLDtrack' = piecewise( 50 * (1 - OVRLDtrack) , (( 1 / (1 + K_mCSQN / Ca_JSR) > CSQNthresh) && (OVRLDtrack3 < 0.37) && (APtrack3 < 0.37 )), -(0.5) * OVRLDtrack );
  OVRLDtrack2' = piecewise( 50 * (1 - OVRLDtrack2) , ( OVRLDtrack > Logicthresh) && (OVRLDtrack2 < Logicthresh ), -(0.5) * OVRLDtrack2 );
  OVRLDtrack3' = piecewise( 50 * (1 - OVRLDtrack3) , ( OVRLDtrack > Logicthresh) && (OVRLDtrack3 < Logicthresh ), -(0.01) * OVRLDtrack3 );

  // Variable initializations:
  G_rel_max = 60000;
  G_rel_overload = 4000;
  tau_tr = 0.18;
  K_mrel = 0.0008;
  delta_Ca_ith = 0.00018;
  CSQN_max = 10;
  K_mCSQN = 0.8;
  K_mup = 0.00092;
  I_up = 5;
  Ca_NSR_max = 15;
  time_ = ;
  F = ;
  Cai = 0.00034209;
  Cao = 1.8;
  Ca_JSR = 0.8204291;
  Ca_NSR = 2.7872629;
  V_myo = ;
  A_cap = ;
  i_NaCa = ;
  i_CaCa = ;
  i_p_Ca = ;
  i_Ca_b = ;
  i_Ca_T = ;
  K_mTn = 0.0005;
  K_mCMDN = 0.00238;
  Tn_max = 0.07;
  CMDN_max = 0.05;
  dVdt = ;
  APtrack = 3.7458e-87;
  APtrack2 = 2.07066e-86;
  APtrack3 = 0.01924195;
  Cainfluxtrack = 1.660129e-87;
  OVRLDtrack = 1.97626e-323;
  OVRLDtrack2 = -2.470328e-323;
  OVRLDtrack3 = 2.2645e-282;
  CSQNthresh = 0.7;
  Logicthresh = 0.98;
end

model viswanathan_1999_epi__ionic_concentrations(Nai, Nao, Ki, Ko, A_cap, V_myo, time_, F, i_Na, i_CaNa, i_Na_b, i_ns_Na, i_NaCa, i_NaK, i_CaK, i_Kr, i_Ks, i_K1, i_Kp, i_K_ATP, i_ns_K, i_to)

  // Assignment Rules:
  V_myo := 0.68 * volume;

  // Rate Rules:
  Nai' = (-(0.001) * (i_Na + i_CaNa + i_Na_b + i_ns_Na + i_NaCa * 3 + i_NaK * 3) * A_cap) / (V_myo * F);
  Ki' = (-(0.001) * (i_CaK + i_Kr + i_Ks + i_K1 + i_Kp + i_K_ATP + i_to + i_ns_K + - i_NaK * 2) * A_cap) / (V_myo * F);

  // Variable initializations:
  Nai = 14.177596;
  Nao = 132;
  Ki = 138.37949;
  Ko = 4.5;
  A_cap = 1.434e-7;
  preplength = 0.001;
  radius = 1.1e-4;
  time_ = ;
  F = ;
  i_Na = ;
  i_CaNa = ;
  i_Na_b = ;
  i_ns_Na = ;
  i_NaCa = ;
  i_NaK = ;
  i_CaK = ;
  i_Kr = ;
  i_Ks = ;
  i_K1 = ;
  i_Kp = ;
  i_K_ATP = ;
  i_ns_K = ;
  i_to = ;

  // Unit definitions:
  unit volume = litre;
end

model *viswanathan_1999_epi____main()

  // Sub-modules, and any changes to those submodules:
  environment: viswanathan_1999_epi__environment(time_);
  membrane: viswanathan_1999_epi__membrane(V, R, T, F, time_, i_Na, i_Ca_L, i_Ca_T, i_Kr, i_Ks, i_K_ATP, i_to, i_K1, i_Kp, i_p_Ca, i_Na_b, i_Ca_b, i_NaK, i_NaCa, i_ns_Ca, dVdt);
  fast_sodium_current: viswanathan_1999_epi__fast_sodium_current(i_Na, E_Na, time_, V, R, F, T, Nai, Nao, m, h, j);
  L_type_Ca_channel: viswanathan_1999_epi__L_type_Ca_channel(i_Ca_L, i_CaCa, i_CaK, i_CaNa, gamma_Nai, gamma_Nao, gamma_Ki, gamma_Ko, time_, V, Cai, R, T, F, Cao, Nao, Ko, Nai, Ki, d, f, f_Ca);
  T_type_Ca_channel: viswanathan_1999_epi__T_type_Ca_channel(i_Ca_T, E_Ca, time_, V, b, g);
  rapid_delayed_rectifier_potassium_current: viswanathan_1999_epi__rapid_delayed_rectifier_potassium_current(i_Kr, E_K, time_, V, Ko, xr);
  slow_delayed_rectifier_potassium_current: viswanathan_1999_epi__slow_delayed_rectifier_potassium_current(i_Ks, time_, V, R, T, F, Ko, Ki, Nao, Nai, Cai, xs1, xs2);
  time_independent_potassium_current: viswanathan_1999_epi__time_independent_potassium_current(i_K1, E_K, V, Ko, Ki, R, T, F, K1_infinity);
  plateau_potassium_current: viswanathan_1999_epi__plateau_potassium_current(i_Kp, V, E_K);
  ATP_sensitive_potassium_current: viswanathan_1999_epi__ATP_sensitive_potassium_current(i_K_ATP, V, Ko, E_K);
  transient_outward_current: viswanathan_1999_epi__transient_outward_current(i_to, E_K, V, time_, zdv, ydv);
  sarcolemmal_calcium_pump: viswanathan_1999_epi__sarcolemmal_calcium_pump(i_p_Ca, Cai);
  sodium_background_current: viswanathan_1999_epi__sodium_background_current(i_Na_b, V, E_Na);
  calcium_background_current: viswanathan_1999_epi__calcium_background_current(i_Ca_b, E_Ca, V, R, T, F, Cai, Cao);
  sodium_potassium_pump: viswanathan_1999_epi__sodium_potassium_pump(i_NaK, V, R, T, F, Nai, Nao, Ko);
  non_specific_calcium_activated_current: viswanathan_1999_epi__non_specific_calcium_activated_current(i_ns_Ca, i_ns_Na, i_ns_K, gamma_Nai, gamma_Nao, gamma_Ki, gamma_Ko, R, T, F, Cao, Nao, Ko, Nai, Ki, time_, Cai, V);
  Na_Ca_exchanger: viswanathan_1999_epi__Na_Ca_exchanger(i_NaCa, V, R, T, F, Nai, Nao, Cai, Cao, n_NaCa);
  calcium_dynamics: viswanathan_1999_epi__calcium_dynamics(i_rel, i_up, i_leak, i_tr, time_, F, Cai, Cao, Ca_JSR, Ca_NSR, V_myo, A_cap, i_NaCa, i_CaCa, i_p_Ca, i_Ca_b, i_Ca_T, dVdt);
  ionic_concentrations: viswanathan_1999_epi__ionic_concentrations(Nai, Nao, Ki, Ko, A_cap, V_myo, time_, F, i_Na, i_CaNa, i_Na_b, i_ns_Na, i_NaCa, i_NaK, i_CaK, i_Kr, i_Ks, i_K1, i_Kp, i_K_ATP, i_ns_K, i_to);
end