"Reveal the top card of your stack. You may install that card, lowering the install cost by $10, if able; otherwise, trash it."
So, let's say I reveal a Toolbox, $9.
- Do I get to install it for free?
- Does "if able" modify the discount clause? I can't actually lower the cost by 10. So I could pay retail price for it, since the event still says I may install it?
- Or, since I can't fulfill all clauses which precede "if able," do I have to trash it?
The second two interpretations seem unlikely to me, since it seems that the intention would be to test run for an expensive program such as Morningstar or Femme, let it go to the top of the deck, then next turn install it for free. There's also some pretty expensive hardware out there, but again, I think it's unlikely that this card was printed if the only fully legal targets for it were Monolith and Blackguard.
Basing interpretations on subjective perception of "Rules As Intended," is a specious argument, so I remain tentative.