Input (grade 13): THX 1138 was the first feature-length film directed by Lucas, developed from his student film Electronic Labyrinth: THX 1138 4EB, which he made in 1967 while attending the University of Southern California.
Output (grade 6): It was based on a short film Lucas made in college in 1967 called "Electric Labyrinth THX 1138 4EB".