ly, one possiblc3 mode of interaction bctwccn the the problLm solver and the dntn base is as follows. A list is maintained of c~cry ;\ssumptioll set disco\rcrcd to bc contradictory. Whcncvcr the problem solver discovers Iwo val~~cs with contt.adictr~ry assumptions, the combined assumption set is placed on this list, and cvcry vaIlIC b,iscd on it or any of its super sets is crascd from the daL\ ...