{"id":"ba-substring-equivalence","text":"`\"ba\" not in s` is equivalent to \"every 'a' precedes every 'b'\" when the input contains only 'a' and 'b' — the only way to violate the ordering is a b-to-a transition, which is exactly the substring \"ba\".","truth_value":"IN","source":"entries/2026/06/06/check-if-all-as-appears-before-all-bs-solution.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"ba-substring-equivalence","truth_value":"IN","reason":"premise"}]}}