CONTRIBUTORS

1) Fixed bug in Defs.merge_edges_1.
2) Major optimization of Defs.define: do not store dependencies between constants that
cannot introduce cycles anyway. In that way, the cycle test adds almost no overhead to
theories that define their constants in HOL-light / HOL4 style.
3) Cleaned up Defs.graph, no superfluous name tags are stored anymore.

* May 2005: Rafal Kolanski, NICTA
  Substantially improved retrieval of facts from theory/proof context.

* May 2005: Florian Haftmann, TUM
  Several new antiquotation.

* February 2005: Lucas Dixon, University of Edinburgh
  Substantially improved subst method.

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