Swordfish
When a digit's candidates in three rows are confined to the same three columns, eliminate that candidate from the other cells in those columns.
All candidates have been entered in the empty cells.
In each row in A, candidate digit 2 appears only in the 3 columns in B. Because the 3 instances of digit 2 in the 3 rows in A cannot occupy the same column, one is in each of the 3 columns in B. Therefore, remove candidate digit 2 marked × in the 3 columns in B.