What is the composition with an artist of Henry Purdy, a year smaller than 2002, and a mint more than 1,998?
CREATE TABLE "provincial_flowers" (
  "year" real,
  "artist" text,
  "composition" text,
  "mintage" real,
  "issue_price" text
);
SELECT "composition" FROM "provincial_flowers" WHERE "year"<2002 AND "mintage">'1,998' AND "artist"='henry purdy';