We prove the Ptolemaean inequality andPtolemaeus' theorem in the closure of complex hyperbolic planes endowed with theCygan metric.
Complex hyperbolic plane, Cygan metric, Ptolemaean inequality, Ptolemaeus' theorem
PLATIS, IOANNIS D. and SÖNMEZ, NİLGÜN
"The Ptolemaean inequality in the closure of complex hyperbolic planes,"
Turkish Journal of Mathematics: Vol. 41:
5, Article 2.
Available at: https://journals.tubitak.gov.tr/math/vol41/iss5/2