> David L. Willson writes: > > - Every ray must be perpendicular to every other ray. > > Clarifiers, if needed: > > - "A ray is not considered perpendicular to itself, so a koan > >with only one pyramid cannot have the BN." > > (you need this, of course as per the obvious recent discussion re > ambiguity; I'd probably default to mastering it with single-ray koans > = true, myself, but that's my bias). > > Needed clarification: are overlapping rays considered the same ray or > different rays? This is, clearly, really important -- with it, a > true > koan can have any number of pyramids > 1, without it, it can only > have > 2 or three pyramids. I consider(ed) overlapping rays to be parallel to one another. I saw the limitation of numbers, and was happy with that, because I wanted a geometrically clever rule, that would also be as simple as possible. I was very disappointed at my failure to lead the students to flat-pip-total = square of upright-pip-total a week ago. :-( I'm happy that they got this one. --David