+ <dt><a name="DAG"><b>DAG</b></a></dt>
+ <dd>Directed Acyclic Graph</dd>
+ <dt><a name="Derived_Pointer"><b>Derived Pointer</b></a></dt>
+ <dd>A pointer to the interior of an object, such that a garbage collector
+ is unable to use the pointer for reachability analysis. While a derived
+ pointer is live, the corresponding object pointer must be kept in a root,
+ otherwise the collector might free the referenced object. With copying
+ collectors, derived pointers pose an additional hazard that they may be
+ invalidated at any <a href="Safe_Point">safe point</a>. This term is used in
+ opposition to <a href="#Object_Pointer">object pointer</a>.</dd>