<?xml version="1.0" encoding="UTF-8"?>
<sbml xmlns="http://www.sbml.org/sbml/level2/version4" level="2" version="4">
    <model id="delayexample">
        <listOfCompartments>
            <compartment id="cell" size="1"/>
        </listOfCompartments>
        <listOfSpecies>
            <species id="P" compartment="cell" initialConcentration="0"/>
        </listOfSpecies>
        <listOfParameters>
            <parameter id="tau"     value="1"   units="second"/>
            <parameter id="m"       value="0.5" units="dimensionless"/>
            <parameter id="q"       value="1"   units="dimensionless"/>
            <parameter id="delta_t" value="1"   units="second"/>
        </listOfParameters>
        <listOfRules>
            <rateRule variable="P">
                <math xmlns="http://www.w3.org/1998/Math/MathML">
                  <apply>
                    <divide/>
                    <apply>
                      <minus/>
                      <apply>
                        <divide/>
                        <cn> 1 </cn>
                        <apply>
                          <plus/>
                          <cn> 1 </cn>
                          <apply>
                            <times/>
                            <ci> m </ci>
                            <apply>
                              <power/>
                              <apply>
                                <csymbol encoding="text" 
                                         definitionURL="http://www.sbml.org/sbml/symbols/delay">
                                    delay
                                </csymbol>
                                <ci> P </ci>
                                <ci> delta_t </ci>
                              </apply>
                              <ci> q </ci>
                            </apply>
                          </apply>
                        </apply>
                      </apply>
                      <ci> P </ci>
                    </apply>
                    <ci> tau </ci>
                  </apply>
                </math>
            </rateRule>
        </listOfRules>
    </model>
</sbml>
