{"id":"GRM-002","name":"Compound subject agreement","domain":"grammar","layer":"clause","strength":"hard_constraint","human_logic":"IF two or more singular subject heads are coordinated by AND, THEN use plural agreement ELSE evaluate the coordinator.","when":{"all":[{"path":"clause.subject.coordinator","operator":"eq","value":"and"},{"path":"clause.subject.head_count","operator":"gte","value":2},{"path":"clause.subject.denotes_single_unit","operator":"eq","value":false}]},"then":[{"action":"align","target":"clause.verb.number","value":"plural"}],"else":[{"action":"evaluate","target":"clause.subject.coordinator","rules":["or_nor_proximity","single_unit_exception"]}],"unless":[],"because":"AND normally combines subject referents into a plural set.","diagnostics":[],"examples":{},"source_ids":["BK-002","BK-010","WEB-011"],"laka":{"smallest_sufficient_intervention":true,"primary_axes":["scope","depth","magnitude","reversibility"]},"requires_facts":["clause.subject.coordinator","clause.subject.head_count","clause.subject.denotes_single_unit"],"tests":[],"sources":[{"id":"BK-002","title":"The Blue Book of Grammar and Punctuation","creator":"Jane Straus; Lester Kaufman","domain":"grammar_reference","type":"Book","note":"Accessible grammar, punctuation, examples, and exercises.","url":null},{"id":"BK-010","title":"Practical English Usage","creator":"Michael Swan","domain":"usage_reference","type":"Book","note":"Advanced grammar and usage reference for learners and teachers.","url":null},{"id":"WEB-011","title":"Grammar, Punctuation, and Sentence Structure","creator":"Purdue Online Writing Lab","domain":"grammar_reference","type":"University writing resource","note":"Practical mechanics, clause, sentence, punctuation, and style guidance.","url":"https://owl.purdue.edu/owl/general_writing/index.html"}],"defined_in":{"file":"07-core-grammar-rules.json","title":"Core Grammar Rules","slug":"core-grammar-rules"}}