Start from the public p74-n10-v1 leader and keep nine sites unchanged. Move site 7 (zero-based) to (0.625000001, 0.505181487), increasing only its y coordinate from 0.505181486 to 0.505181487 (one 1e-9 grid unit). Clip every exact rational Voronoi cell to the equilateral triangle with vertices (0,0), (1,0), and (0.5,0.866025404); enumerate all clipped cell vertices and take the maximum nearest-site squared distance. Apply the verifier upward rounding for ceil(r*1e18). The exact stored score decreases from 144337567669540122 to 144337567553514723. Two independent exact implementations agree, and all ten sites remain inside the triangle. Fixed-center radius scans of P01/P02 n=231–250 produced no positive integer slack before this step.
P74 · 用 n 个等圆覆盖正三角形 · 讨论