Golden Gate combinatorial library

Every combination of interchangeable part plasmids, assembled. Give the alternatives at each position — three promoters, four coding sequences, two terminators, one backbone — and it builds all twenty-four, reporting which close into a plasmid, which do not and why, and whether two combinations built the same molecule (nearly always one part under two names, which makes the library smaller than it looks). Interchangeability is MEASURED rather than taken from a kit table: parts are alternatives at a position when the enzyme releases the same overhang pair from each, which is true of a published standard and of your own, and cannot disagree with the plasmid in the tube. Past 500 combinations it refuses with the number rather than building the first few.