Loop
From Sudopedia, the Free Sudoku Reference Guide
Jump to navigationJump to searchA loop is a cyclic pattern of linked cells or candidates.
Loops are usually represented by chains, where the first and the last cell are the same. Like a chain, implications in a loop can either travel in a single direction or in both directions. A bidirectional loop is better known as a Nice Loop.
Examples of loops are:
Notation systems are similar to chain notation, with Nice Loop notation especially designed for loops.
