<?xml version="1.0" encoding="UTF-8"?>
<sbml xmlns="http://www.sbml.org/sbml/level1" level="1" version="1">
  <model>
    <listOfCompartments>
      <compartment name="cell" volume="1"/>
    </listOfCompartments>
    <listOfSpecies>
      <specie name="s1" compartment="cell" initialAmount="4"/>
      <specie name="s2" compartment="cell" initialAmount="2"/>
      <specie name="x0" compartment="cell" initialAmount="1"/>
      <specie name="x1" compartment="cell" initialAmount="0"/>
    </listOfSpecies>
    <listOfParameters>
      <parameter name="k1" value="1.2"/>
      <parameter name="k2" value="1000"/>
      <parameter name="k3" value="3000"/>
      <parameter name="k4" value="4.5"/>
    </listOfParameters>
    <listOfRules>
      <parameterRule name="t" formula="s1 + s2"/>
      <parameterRule name="k" formula="k3/k2"/>
      <specieConcentrationRule specie="s2" formula="k * t/(1 + k)"/>
      <specieConcentrationRule specie="s1" formula="t - s2"/>
    </listOfRules>
    <listOfReactions>
      <reaction name="j1">
        <listOfReactants>
          <specieReference specie="x0"/>
        </listOfReactants>
        <listOfProducts>
          <specieReference specie="s1"/>
        </listOfProducts>
        <kineticLaw formula="k1 * x0"/>
      </reaction>
      <reaction name="j3">
        <listOfReactants>
          <specieReference specie="s2"/>
        </listOfReactants>
        <listOfProducts>
          <specieReference specie="x1"/>
        </listOfProducts>
        <kineticLaw formula="k4 * s2"/>
      </reaction>
    </listOfReactions>
  </model>
</sbml>
