Pointing Thermo
Digits strictly increase from bulb to tip. Count outward along the ray by the tip digit: that cell contains the bulb digit.
Parameters
| Parameter | Meaning | Default |
|---|---|---|
| line | The cells in order, for example r1c1-r1c2-r1c3. | Required. |
| ray | The cells along the ray, nearest first. | Required. |
Maths
Class: first-order.
The shared predicates define the notation and every named predicate.
|line|>0 ∧ (∀i∈[0,|line|-1): D(line[i])<D(line[i+1]))
∧ let x=D(line[|line|-1]); 1<=x<=|ray| ∧ D(ray[x-1])=D(line[0])
Digits strictly increase along cells. The tip digit names a one-based position on ray whose digit equals the bulb digit. The named position must be within the ray.
Example
---
format: open-rules
title: Pointing Thermo example
setter: Example
source: ""
case: ""
library: https://rules.sudoku-sleuth.com/
status: read
---
```rules
sudoku 9x9
pointing-thermo r1c1-r1c2 ray ["r1c3","r1c4"]
```
Satisfies the rule: r1c1=1, r1c2=2, r1c4=1, r1c3=3. The tip 2 selects the second ray cell, which matches the bulb 1.
Breaks the rule: r1c1=1, r1c2=2, r1c4=4, r1c3=3. The selected ray cell contains 4 instead of the bulb 1.