Tabling

Tabling is a solving technique which is not used by human players but by computer programs. The program builds a table of implications for the true and false states of each remaining candidate in the grid.

The primary aim of tabling is to find a candidate that causes a contradiction. The program can then build a chain that proves this contradiction.

Alternatively, the tables can be used to find verities, which are implications that occur for all alternative candidates in a constraint. Since multiple chains are required to prove a verity, this aspect of tabling is only used when no contradictions can be found.