Jürgen Avenhaus Thomas Hillenbrand Bernd Löchner On using ground joinable equations in equational theorem proving. 217-233 2003 36 J. Symb. Comput. 1-2 http://dx.doi.org/10.1016/S0747-7171(03)00024-5 db/journals/jsc/jsc36.html#AvenhausHL03