Quadruple
The surrounding cells contain every listed digit, including the stated number of copies.
Parameters
| Parameter | Meaning | Default |
|---|---|---|
| cells | The marked cells, for example r1c1-r1c2-r2c2. | Required. |
| digits | The allowed or required digits, listed explicitly; repeats in the list count where the rule says so. | Required. |
Maths
Class: with aggregates.
The shared predicates define the notation and every named predicate.
∀d∈digits: countWhere(cells,λc:cell: D(c)=d)>=multiplicity(digits,d)
For every listed digit d, its occurrences among cells are at least its multiplicity in digits. Extra copies and unlisted digits are allowed by this check.
Example
---
format: open-rules
title: Quadruple example
setter: Example
source: ""
case: ""
library: https://rules.sudoku-sleuth.com/
status: read
---
```rules
sudoku 9x9
quadruple r1c1-r1c2-r2c1-r2c2 digits [1,2]
```
Satisfies the rule: r1c1=1, r1c2=2, r2c1=1, r2c2=1. Every listed digit appears around the clue.
Breaks the rule: r1c1=1, r1c2=3, r2c1=1, r2c2=1. A listed digit is missing around the clue.