gistfile1.xml

<score>
    <measure>
        <note pitch="c"/>
        <note pitch="c"/>
        <note pitch="g"/>
        <note pitch="g"/>
    </measure>
    <measure>
        <note pitch="a"/>
        <note pitch="a"/>
        <note pitch="g" dur="2"/>
    </measure>
    <sb xml:id="mysb"/> <!-- system break -->
    <measure>
        <note pitch="f"/>
        <note pitch="f"/>
        <note pitch="e"/>
        <note pitch="e"/>
    </measure>
    <measure>
        <note pitch="d" xml:id="d1"/>
        <note pitch="d"/>
        <note pitch="c" dur="2"/>
    </measure>
</score>

slur.xml

<score>
    <measure>
        <note pitch="c"/>
        <note pitch="c"/>
        <note pitch="g"/>
        <note pitch="g"/>
    </measure>
    <measure>
        <note pitch="a"/>
        <note pitch="a"/>
        <note pitch="g" dur="2"/>
    </measure>
    <sb xml:id="mysb"/> <!-- system break -->
    <measure>
        <note pitch="f" xml:id="f1"/>
        <note pitch="f" xml:id="f2"/>
        <note pitch="e"/>
        <note pitch="e"/>
    </measure>
    <measure>
        <note pitch="d" xml:id="d1"/>
        <note pitch="d"/>
        <note pitch="c" dur="2"/>
    </measure>
    <slur from="f1" to="d1"/>
</score>