tapestry-core/src/test/app1/NestedForm.tml

<t:border xmlns:t="http://tapestry.apache.org/schema/tapestry_5_0_0.xsd">
    <h1>Nested Form Demo</h1>

    <t:form t:id="outer">
        <t:form t:id="inner"/>
    </t:form>

</t:border>