{"id":"PUN-003","name":"Comma before coordinating conjunction","domain":"punctuation","layer":"sentence","strength":"context_default","human_logic":"IF a coordinating conjunction joins two independent clauses, THEN place a comma before it unless the clauses are very short and unambiguous ELSE retain.","when":{"all":[{"path":"coordination.joins","operator":"eq","value":"independent_clauses"},{"path":"coordination.marker","operator":"in","value":["and","but","or","nor","for","so","yet"]}]},"then":[{"action":"insert","target":"coordination.pre_marker_punctuation","value":","}],"else":[{"action":"retain","target":"current_text","reason":"No triggering condition is present."}],"unless":[{"all":[{"path":"coordination.clauses_short","operator":"eq","value":true},{"path":"coordination.ambiguity","operator":"eq","value":false}]}],"because":"The comma displays the boundary while the conjunction displays the relationship.","diagnostics":[],"examples":{},"source_ids":["BK-002","BK-007","WEB-011"],"laka":{"smallest_sufficient_intervention":true,"primary_axes":["scope","depth","magnitude","reversibility"]},"requires_facts":["coordination.joins","coordination.marker"],"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-007","title":"The Copyeditor's Handbook","creator":"Amy Einsohn; Marilyn Schwartz","domain":"copyediting","type":"Book","note":"Professional copyediting practice, grammar, and editorial process.","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":"08-punctuation-rules.json","title":"Punctuation as Meaning and Boundary","slug":"punctuation-rules"}}