<?xml version="1.0" encoding="UTF-8"?>
<sbml xmlns="http://www.sbml.org/sbml/level3/version1/core" level="3" version="1">
    <model id="Example" substanceUnits="mole" volumeUnits="litre"
           timeUnits="second" extentUnits="mole">
        <listOfUnitDefinitions>
            <unitDefinition id="conc">
                <listOfUnits>
                    <unit kind="mole" multiplier="1" scale="0" exponent="1"/>
                    <unit kind="litre" multiplier="1" scale="0" exponent="-1"/>             
                </listOfUnits>
            </unitDefinition>
        </listOfUnitDefinitions>
        <listOfFunctionDefinitions>
            <functionDefinition id="f">
                <math xmlns="http://www.w3.org/1998/Math/MathML"
                      xmlns:sbml="http://www.sbml.org/sbml/level3/version1/core">
                    <lambda>
                        <bvar>
                            <ci> x </ci>
                        </bvar>
                        <apply>
                            <times/>
                            <ci> x </ci>
                            <cn sbml:units="conc"> 2 </cn>
                        </apply>
                    </lambda>
                </math>
            </functionDefinition>
        </listOfFunctionDefinitions>
        <listOfCompartments>
            <compartment id="compartmentOne" size="1" spatialDimensions="3" constant="true"/>
        </listOfCompartments>
        <listOfSpecies>
            <species id="S1" initialConcentration="1" compartment="compartmentOne"
                     hasOnlySubstanceUnits="false" boundaryCondition="false"
                     constant="false"/>
            <species id="S2" initialConcentration="0" compartment="compartmentOne"
                     hasOnlySubstanceUnits="false" boundaryCondition="false"
                     constant="false"/>
        </listOfSpecies>
        <listOfParameters>
            <parameter id="t" value = "1" constant="true"/>
        </listOfParameters>
        <listOfReactions>
            <reaction id="reaction_1" reversible="false" fast="false">
                <listOfReactants>
                    <speciesReference species="S1" stoichiometry="1" constant="true"/>
                </listOfReactants>
                <listOfProducts>
                    <speciesReference species="S2" stoichiometry="1" constant="true"/>
                </listOfProducts>
                <kineticLaw>
                    <math xmlns="http://www.w3.org/1998/Math/MathML">
                        <apply>
                        <divide/>
                            <apply>
                                <times/>
                                <apply>
                                    <ci> f </ci>
                                    <ci> S1 </ci>
                                </apply>
                                <ci> compartmentOne </ci>
                            </apply>
                            <ci> t</ci>
                        </apply>
                    </math>
                </kineticLaw>
            </reaction>
        </listOfReactions>
    </model>
</sbml>
