This bead is at Row 2. Column 4 has a bead at Row 2 too → red (=).
- Column 6 goes down to Row 2, so use Rule 2: look 2 columns back, at Column 4.
- Column 4 has a bead at Row 2 too → red (=).
Common table reading watchout: Thinking "no bead at this row" means blue. It is blue only when Column 4 stopped exactly one row above this bead.