17. The computer program product of claim 16 wherein instructions to translate the components of the expanded set of sellable units that do not include a crossed combination of priceable units comprises instructions to: add a context free grammar rule for each of the sellable units.
17. The computer program product of claim 16 wherein instructions to translate the components of the expanded set of sellable units that do not include a crossed combination of priceable units comprises instructions to: add a context free grammar rule for each of the sellable units. 19. The computer program product of claim 17 wherein faring-atoms are represented as sets of flights and instructions to add a context-free grammar rule comprises: add a rule for each faring-atom FA[k] of length L[k] as: FA[k]==>Flight[k][1] . . . Flight[k][L[k]], wherein the symbol “==>” denotes producing.