{"id":"counter-subtraction-as-subset-check","text":"`countCharacters` uses `not (Counter(word) - chars_count)` as a sub-multiset containment check — Counter subtraction drops zero/negative counts, so emptiness means every character in the word is available with sufficient multiplicity.","truth_value":"IN","source":"entries/2026/06/06/find-words-that-can-be-formed-by-characters-solution.md","source_url":"","source_hash":"","justifications":[],"dependents":["counter-subtraction-is-multiset-containment-test"],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"counter-subtraction-as-subset-check","truth_value":"IN","reason":"premise"}]}}