<?xml version="1.0" encoding="UTF-8"?>
<sbml xmlns="http://www.sbml.org/sbml/level2/version4" level="2" version="4"
      xmlns:math="http://www.w3.org/1998/Math/MathML">
    <model id="assignmentrules">
        <listOfUnitDefinitions>
            <unitDefinition id="per_second">
                <listOfUnits>
                    <unit kind="second" exponent="-1"/>
                </listOfUnits>
            </unitDefinition>
        </listOfUnitDefinitions>
        <listOfCompartments>
            <compartment id="cell" size="1"/>
        </listOfCompartments>
        <listOfSpecies>
            <species id="X0" compartment="cell" initialConcentration="1"/>
            <species id="X1" compartment="cell" initialConcentration="0"/>
            <species id="T"  compartment="cell" initialConcentration="0"/>
            <species id="S1" compartment="cell" initialConcentration="0"/>
            <species id="S2" compartment="cell" initialConcentration="0"/>
        </listOfSpecies>
        <listOfParameters>
            <parameter id="Keq" value="2.5" units="dimensionless"/>
        </listOfParameters>
        <listOfRules>
            <assignmentRule variable="S1">
                <math xmlns="http://www.w3.org/1998/Math/MathML">
                    <apply>
                        <divide/>
                        <ci> T </ci>
                        <apply>
                            <plus/>
                            <cn> 1 </cn>
                            <ci> Keq </ci>
                        </apply>
                    </apply>
                </math>
            </assignmentRule>
            <assignmentRule variable="S2">
                <math xmlns="http://www.w3.org/1998/Math/MathML">
                    <apply>
                        <times/>
                        <ci> Keq </ci>
                        <ci> S1 </ci>
                    </apply>
                </math>
            </assignmentRule>
        </listOfRules>
        <listOfReactions>
            <reaction id="in">
                <listOfReactants>
                    <speciesReference species="X0"/>
                </listOfReactants>
                <listOfProducts>
                    <speciesReference species="T"/>
                </listOfProducts>
                <kineticLaw>
                    <math xmlns="http://www.w3.org/1998/Math/MathML">
                        <apply>
                            <times/>
                            <ci> k1 </ci>
                            <ci> X0 </ci>
                            <ci> cell </ci>
                        </apply>
                    </math>
                    <listOfParameters>
                        <parameter id="k1" value="0.1" units="per_second"/>
                    </listOfParameters>
                </kineticLaw>
            </reaction>
            <reaction id="out">
                <listOfReactants>
                    <speciesReference species="T"/>
                </listOfReactants>
                <listOfProducts>
                    <speciesReference species="X1"/>
                </listOfProducts>
                <listOfModifiers>
                    <modifierSpeciesReference species="S2"/>
                </listOfModifiers>
                <kineticLaw>
                    <math xmlns="http://www.w3.org/1998/Math/MathML">
                        <apply>
                            <times/>
                            <ci> k2 </ci>
                            <ci> S2 </ci>
                            <ci> cell </ci>
                        </apply>
                    </math>
                    <listOfParameters>
                        <parameter id="k2" value="0.15" units="per_second"/>
                    </listOfParameters>
                </kineticLaw>
            </reaction>
        </listOfReactions>
    </model>
</sbml>
