WALK, TRAIL, SIMPLE and ACYCLIC

A path mode constrains the entire path, including its fixed and repeated segments.

Mode	Repetition rule
WALK	Nodes and edges may repeat, subject to MATCH-level constraints
TRAIL	No repeated edge
SIMPLE	No repeated node, except the start may reappear as the final node of a cycle
ACYCLIC	No repeated node

MATCH REPEATABLE ELEMENTS p = ACYCLIC (a {name: 'Alice'})-[:Knows]-{1,3}(b)
RETURN b.name AS destination, PATH_LENGTH(p) AS hops ORDER BY hops;

WALK is the default path mode, but the default DIFFERENT EDGES match mode still forbids edge reuse within one MATCH. Specify REPEATABLE ELEMENTS when the distinction matters.

A mode inside a repeated parenthesized group constrains each iteration. It does not automatically make an unbounded outer WALK finite. Choose an explicit finite upper bound when composing patterns whose termination cannot be proven.