begin name
tyson9
end name

begin reactions
r0 {1.0}X = {1.0}R
r1 {1.0}$EXTERNAL = {1.0}X
r2 {1.0}R = {1.0}$EXTERNAL
r3 {1.0}$EXTERNAL = {1.0}$EXTERNAL
r4 {1.0}$EXTERNAL = {1.0}$EXTERNAL
end reactions

begin rate equations
r0 = env*(Ep*k0 + k0prime)*X[t]
r1 = env*k1*S
r2 = env*k2*R[t]
r3 = (E*env*k3*R[t])/(E + Km3)
r4 = (env*Ep*k4)/(Ep + Km4)
end rate equations

begin parameters
Et = 1.0
J3 = 0.05
J4 = 0.05
k0 = 0.4
k0prime = 0.01
k1 = 1.0
k2 = 1.0
k3 = 1.0
k4 = 0.3
S = 0.0
env = 1.0
end parameters

begin initial conditions
R[0] = Ri
X[0] = Xi
end initial conditions

begin initial values
Ri = 0.0
Xi = 0.0
end initial values

begin assignment rules
E := -Ep + Et
Ep := Et*goldbeterkoshland[k3*R[t], k4, J3, J4]
Km4 := Et*J4
Km3 := Et*J3
end assignment rules

begin function definitions
goldbeterkoshland[v1_,v2_,J1_,J2_] := (2*J2*v1)/(-v1 + J2*v1 + v2 + J1*v2 + Sqrt[-4*J2*v1*(-v1 + v2) + (-v1 + J2*v1 + v2 + J1*v2)^2])
end function definitions

begin events
end events

begin process annotations
end process annotations

begin species annotations
end species annotations

begin units
end units