trex

digraph G {
subgraph definition {
TrexDefItem → TrexDef;
TrexDef → TrexDefItem [dir=both,arrowtail=box];
}

subgraph parameter {
    TrexParamItem;
    TrexParam -> TrexParamItem [label="4x"];
  }

subgraph template {
    TrexTempl -> TrexParam;
    TrexTempl -> TrexTemplatePart [dir=both,arrowtail=box];
    TrexTemplatePart -> TrexTempl;
    TrexTemplatePart -> TrexVal [arrowhead=inv];
  }

subgraph value {
    TrexValItem -> TrexVal;
    TrexValArray -> TrexValItem [dir=both,arrowtail=box];
    TrexVal -> TrexValArray [dir=both,arrowtail=box];
    TrexVal -> TrexDef;
  }
}