Question: What English author is known for a long series of novels that first started in 1971 and ended in 2015, where a portion of the novels focus on witches?
{'answer': 'Terry Pratchett', 'supporting_facts': [['Witches (Discworld)', 0], ['Terry Pratchett', 0], ['Terry Pratchett', 1], ['Terry Pratchett', 2], ['Terry Pratchett', 5]]}