Question: Find the number of papers published by the institution "University of Pennsylvania".
Schema: create table inst (instid varchar, name varchar, PRIMARY KEY (instid)); create table authorship (paperid varchar, instid varchar, PRIMARY KEY (paperid)); create table papers (title varchar, paperid varchar, PRIMARY KEY (title))
SQL: select count(distinct t1.title) from papers as t1 join authorship as t2 on t1.paperid = t2.paperid join inst as t3 on t2.instid = t3.instid where t3.name = "university of pennsylvania"