 [arrowtail="empty", dir="back", id="graph1_1_0", class="inheritance", tooltip="SymbObj[U] is a subtype of Term"] ;node2 -> node0 [arrowtail="empty", dir="back", id="graph1_2_0", class="inheritance", tooltip="SymbObj[U] is a subtype of Symbolic"] ;node3 -> node0 [arrowtail="empty", dir="back", id="graph1_3_0", class="inheritance", tooltip="SymbObj[U] is a subtype of Product"] ;node4 -> node0 [arrowtail="empty", dir="back", id="graph1_4_0", class="inheritance", tooltip="SymbObj[U] is a subtype of Serializabl