As you may not know, AS extensively uses through fares, and yes, they are published! There are many through fares that are cheaper (sometimes significantly) than the segments purchased separately. Onward flights in a connecting city must commence <= 4 hours from arrival to retain the through fare otherwise it will revert back to the sum of the segments and the online booking engine is intelligent enough to apply the filed through fare when the conditions are satisfied. Even where through fares are not offered, combining two segments will save a $5.60 Security Fee over booking each segment independently.

If your assumption that AS fares are only constructed as the sum of a series of segments, you would be incorrect. Through fares allow AS to be competitive and offer additional routings through a connecting city without giving huge discounts on the segments to effect them.

James