begin parameters
  R0   100
  L0   500
  A0   100
  kon  0.01
  koff  0.1
  kAon 0.01
  kAoff 0.1
end parameters

begin molecule types
 R(l,a)
 L(r)
 A(r)
end molecule types

begin seed species
  R(l,a)   R0    
  L(r)   L0
  A(r)   A0
end seed species

begin reaction rules
   R(l) + L(r) <-> R(l!1).L(r!1) kon, koff
   R(a) + A(r) <-> R(a!1).A(r!1) kAon, kAoff
end reaction rules

begin observables
  Molecules Rtotal  R()
  Molecules Ltotal  L()
  Molecules Atotal  A()
  Molecules L_unbound  L(r)
  Molecules R_unbound  R(l,a)
  Molecules A_unbound  A(r)
  Molecules L_bound  L(r!+)
  Molecules R_bound  R(l!+)
  Molecules RLA  R().L().A()
  Molecules RA1  A(r!+)
  Molecules RA2  A(r!1).R(a!1)
  Molecules RA3 A().R()
end observables

generate_network();
writeSBML();
simulate_ode({t_end=>50,n_steps=>20});