CREATE TABLE authorship (paperid VARCHAR2, instid VARCHAR2)
CREATE TABLE inst (instid VARCHAR2, name VARCHAR2)
CREATE TABLE papers (title VARCHAR2, paperid VARCHAR2)

Find the number of papers published by the institution 'University of Pennsylvania'.
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"
SELECT COUNT(DISTINCT "t1"."title") FROM "papers" "t1" JOIN "authorship" "t2" ON "t1"."paperid" = "t2"."paperid" JOIN "inst" "t3" ON "University of Pennsylvania" = "t3"."name" AND "t2"."instid" = "t3"."instid"