{"id":"gap-formula-excludes-endpoints","text":"The expression `i - first_seen[c] - 1` counts characters strictly between positions `first_seen[c]` and `i`, excluding both boundary characters.","truth_value":"IN","source":"entries/2026/06/06/largest-substring-between-two-equal-characters-solution.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"gap-formula-excludes-endpoints","truth_value":"IN","reason":"premise"}]}}