MXQ

Introduction Initial Values Start Grid Sub RC Elimination 2-Cell Chains Strange 2C Chains Swordfish Patterns Re-Check/Refresh X-Wing Patterns 7C Swordfish 4-Cell Chains (Row) 4-Cell Chains (Col) Solution Change Tracking Re-Eng. Grids

MXQ Adv. Sudoku

Re-Check/Refresh

After refreshing the 5 highlights, we can see that there is a single 5 in row C at C5 which means all the other 5's in column 5 can be removed. In addition the 4,6 & 7 can be removed from C5.