The last puzzle I published with “anti-quadruples” fully filled each anti-quad circle, providing maximum information about what wasn’t there. This time, a few digits seem to be missing, and most of these circles eliminate very few candidates each.
Rules:
Normal Sudoku rules apply.
Digits within colored circles do not appear in cells touching the circle.
Estimated difficulty: 1 out of 5
Solve on SudokuPad