Ian McEwan, bridge and restricted choice

I am reading Ian McEwan's novel "The Sweet Tooth" and was surprised to see an excellent explanation of a complex logic puzzle in it.  And even more surprised when the author shows off by building a slightly-wrong vignette based on the puzzle, and a better vignette that corrects the problem.

My respect for Mr. McEwan has gone up several fold now. Full details in my bridge blog (don't worry you should understand almost all of it).