Palindrome

The values along the line read the same forwards and backwards.

Parameters

Maths

Class: first-order.

The shared predicates define the notation and every named predicate.

∀i ∈ [0,|line|): V(line[i]) = V(line[mirror(line,i)])

Positions at equal distances from opposite ends have equal values.

Example

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

```rules
sudoku 9x9
palindrome r1c1-r1c2-r2c3-r2c4-r3c4
```

Satisfies the rule: r1c1=1, r1c2=2, r2c3=3, r2c4=2, r3c4=1. 1, 2, 3, 2, 1 reads the same from either end.

Breaks the rule: r1c1=1, r1c2=2, r2c3=3, r2c4=2, r3c4=4. 1, 2, 3, 2, 4 has different end digits.