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 3, 3D Kraken + ALS Chain, Dual Overlap

This logic works like a chain where 2 links are made of ALSs. The ends of the chain then overlap to eliminate the 2 candidates. Alternatively row sets 46r4 can be considered the body of a kraken structure. The set logic notation for the elimination is:

Rank 1(6+7), [12r5 46r6 59c4]x[5n46 6n479 8n4 2b6] 2b6*5n46 => r6c7<>2, r6c9<>2