What is the lowest react of the athlete from the United States who has a lane less than 4?
CREATE TABLE "semifinal_1" (
  "rank" real,
  "lane" real,
  "athlete" text,
  "country" text,
  "time" real,
  "react" real
);
SELECT MIN("react") FROM "semifinal_1" WHERE "country"='united states' AND "lane"<4;