Uc: Convention Cryptics: "Planes, Planes, and Planes", "First In . . .", and "Twelve Fifty Redux"

http://math.uchicago.edu/~wald/con21a.pdf

http://math.uchicago.edu/~wald/con21b.pdf

http://math.uchicago.edu/~wald/con21c.pdf

(My 2021 NPL Con cryptics.)