View source for Set Equivalence Theory

'''Set Equivalence Theory''' (commonly abbreviated to '''SET''', sometimes redundantly '''SET Theory''') is an advanced [[sudoku]] solving technique. It states that if any set of cells 𝐴 is known to contain the same collection of digits as any set of cells 𝐵, then the set difference 𝐴 \ 𝐵 must also contain the same collection of digits as the set difference 𝐵 \ 𝐴. Usually 𝐴 and 𝐵 are chosen to be some union of non-overlapping rows, columns, and 3×3 boxes, meaning that they are known to contain an equal number of every possible digit.

[[Category:Puzzles]]