เราพิสูจน์ว่าถ้า ![{\displaystyle \mathrm {pre} [u]<\mathrm {pre} [v]<\mathrm {post} [v]<\mathrm {post} [u]\,}](https://wikimedia.org/api/rest_v1/media/math/render/svg/b0ff206bf4f368bf78732711c0de3d6e9fea6020)
พิสูจน์: เนื่องจาก Too many requests (f061ab2) If you report this error to the Wikimedia System Administrators, please include the details below.![{\displaystyle \mathrm {pre} [u]<\mathrm {pre} [v]\,}](https://wikimedia.org/api/rest_v1/media/math/render/svg/f371b237a0a203af543e3a11d0ba1766d6c91575)
Error
Request served via cp5021 cp5021, Varnish XID 680244453
Upstream caches: cp5021 int
Error: 429, Too many requests (f061ab2) at Fri, 24 Apr 2026 12:49:46 GMTSensitive client information
IP address: 158.108.32.49![{\displaystyle \mathrm {post} [v]<\mathrm {post} [u]\,}](https://wikimedia.org/api/rest_v1/media/math/render/svg/afd9a1b343df416653958335cfb711a4cb7e3707)
ฉะนั้นจะต้องมี path ใน DFS tree จาก Too many requests (f061ab2) If you report this error to the Wikimedia System Administrators, please include the details below.
Error
Request served via cp5021 cp5021, Varnish XID 670059487
Upstream caches: cp5021 int
Error: 429, Too many requests (f061ab2) at Fri, 24 Apr 2026 12:49:47 GMTSensitive client information
IP address: 158.108.32.49
ดังนั้น
