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 16, AALS Multiloop + Converging Chains

Columns 1 and 2 contain a rank 2 AALS like structure with 1 box and 2 column sets. This then has 2 branches from 2r2 and 9r6 that converge at triplet 2r5c6, which continue as a single rank 1 chain. The end of the chain 6r1 overlaps cell linkset 1n1 to eliminate candidate 6r1c1. at The set logic notation for the elimination is:

Rank 2(8+10), [1r5 2c167 5c1 6c6 9c4 9b4]x[2r25 6r1 9r6 146n1 5n4 45n6] (T)6r1*1n1 => r1c1<>6

=> 6r2c1 => r2c1<>12, r2c48<>6, => 2r2c7, r2c7<>38, r1c9<>2