Added the function to identify the version of knowledge-base.
Added the option of rm_direction.
Revised the implementation of knowledge-base in order to compile a huge knowledge-base.
Changed the name of the component files of knowledge base.
Parallelized the generation of reachable-matrix.
Debugged.
Debugged.
Debugged the function of unification postponement.
Added the function to cancel chainings which need an unification between constants.
Implemented & refactored. (halfway)
Improved the function to cancel invalid chainings.
Refuctored proof_graph.*
Debugged.
Added the function of "hard-term".
Added the function to print the version of Phillip.
Added the function to add paraphrasal axioms.
Added the function to print reachability-matrix for debug.
Revised the process of reachability-matrix creation.
Updated the version of knowledge-base.
Deleted the option of "rm_direction".
Deleted the function to identify the direction of inference.
Performed refactoring.
Debugged.
Added a script to convert XML into HTML of the viewer.
Fixed a bug in a_star_based_enumerator_t, and so on.
Updated the version of Phillip.
Revised the search procedure of lhs::a_star_based_enumerator_t.
Refuctored lhs::a_star_based_enumerator_t.
Fixed bug in knowledge base_t.

Improved the performance of lhs::a_star_based_enumerator_t.