A General Logic for Sudoku

Monster #224 from list 1465

This is part of a set-logic solution to monster puzzle #224 from the 1465 list. The original solution to the puzzle (by ttt) was presented here. The elimination logic has the form:

rank N(n sets+ m linksets), [ cover set list ]x[ cover linkset list ] reason for elimination => results

For more information on notation and set logic eliminations, see quick reference. For a full description of sets and Sudoku set logic, see the SudokuOne.com website. The entire set logic solution is here.

Elimination 11, Complex Structure

This is a complex piece of rank 4 logic where 2 overlap linksets eliminate the candidate at 2r3c7. The logic must therefore have at least 3 linkset triplets to augment the rank of the overlap linksets. The most obvious is the nearby triplet A. Four other triplets are marked with red arrows. The set logic notation for the elimination is:

Rank 4 = 19-15, [4r269 6r36 5c48 7c9 3n5 5n7 7n7 8n357 6b6]x

[2r3 57r5 156r8 4c3 6c4 4c5 2456c7 6c9 4n8 6n49 9n9 4b2] (TTT)2r3*2c7 => r3c7<>2