Unique

All digits in the listed cells are different. Declare each row, column and region that needs this rule.

Parameters

Maths

Class: first-order.

The shared predicates define the notation and every named predicate.

distinct_D(cells)

Different cells in the group have different digits. This does not add missing-digit coverage when the group is shorter than the alphabet.

Example

---
format: open-rules
title: Unique example
setter: Example
source: ""
case: ""
library: https://rules.sudoku-sleuth.com/
status: read
---

```rules
sudoku 9x9
unique r1c1-r1c2
```

Satisfies the rule: r1c1=1, r1c2=2. The marked digits are different.

Breaks the rule: r1c1=1, r1c2=1. The marked digits repeat.