On Saturday, 5 November 2022 at 16:06:52 UTC, cactus wrote: I should have quoted the full comprehensions: all((srt(m, n) in c_np) == (srt(a, b) in c_ap) for (m, a), (n, b) in combinations(na8, 2)) all( srt(m, n) in c_np == srt(a, b) in c_ap) for (m, a), (n, b) in combinations(na8, 2))