Question: what are the variables of boyle's law
[{'answer': 'k is a constant', 'provenance': [{'wikipedia_id': '65891', 'title': "Boyle's law", 'start_paragraph_id': 5, 'start_character': 73, 'end_paragraph_id': 5, 'end_character': 89, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'V is the volume of the gas'}, {'answer': 'P is the pressure of the gas'}, {'provenance': [{'wikipedia_id': '65891', 'title': "Boyle's law", 'start_paragraph_id': 5, 'start_character': 0, 'end_paragraph_id': 5, 'end_character': 89, 'bleu_score': 0.9021315316859231, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8120038845522556544}, 'section': 'Section::::Abstract.'}]}]