3. Consider these documents: Doc 1 breakthrough drug for schizophrenia Doc 2 new schizophrenia drug Doc 3 new approach for treatment of schizophrenia Doc 4 new hopes for schizophrenia patients a. Draw the term-document incidence matrix for this document collection. b. Draw the inverted index representation for this collection. For example, "approach" can be illustrated as follows. approach Given the above document collection, what are the returned results for these queries: 1) schizophrenia AND drug 2) for AND NOT(drug OR approach) c