I actually looked that up on my last reread. It turns out there are several known pentagon tilings, some of which are quite attractive, although of course none use regular pentagons.
I don’t think that actually works. At most, you’ve reduced the measure increase by the inverse-exponential length of the shortest program that rewrites in a way that undoes the impossibility. What kind of serial fiction extrapolating simulator lacks that as a builtin feature, but still works?
Tiled in pentagons? That I want to see. Or… not. Probably not.
I actually looked that up on my last reread. It turns out there are several known pentagon tilings, some of which are quite attractive, although of course none use regular pentagons.
You may also be interested in Uniform tilings in the hyperbolic plane. In this non-euclidean plane, regular pentagon tiling is possible, and, using some mapping to Euclidean space, aesthetically pleasing pictures may be produced.
So we may presume the hallway in question had a vaulted ceiling.
Or that Hogwarts is doing funny things with space, which we know it does regularly.
I was being careful to include at least one logical impossibility in the story so that my writing it could not increase its measure.
I don’t think that actually works. At most, you’ve reduced the measure increase by the inverse-exponential length of the shortest program that rewrites in a way that undoes the impossibility. What kind of serial fiction extrapolating simulator lacks that as a builtin feature, but still works?
But as others have pointed out, that just indicates that that section of Hogwarts is negatively curved. Of course, you say “at least one”, so...
As others have pointed out, it’s not entirely impossible.