Question: who is the mathematician who first use brackets to indicate grouping
[{'answer': 'Christopher Clavius', 'provenance': [{'wikipedia_id': '11219603', 'title': 'Bracket (mathematics)', 'start_paragraph_id': 2, 'start_character': 245, 'end_paragraph_id': 2, 'end_character': 264, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '11219603', 'title': 'Bracket (mathematics)', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 293, 'bleu_score': 0.9560167778278961, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9948450215315739495}, 'section': 'Section::::Abstract.'}]}]