Volume 28 • Number 2 • 2006   • Note on Transformations of Posets with the Same Upper Bound Graph and Minimal Elements Kenjiro Ogawa and Morimasa Tsuchiya Abstract. Two posets with the same canonical poset and the same upper bound graph can be transformed into each other by a finite sequence of two kinds of transformations, called x<y-additions and x<y-deletions on minimal elements. 2000 Mathematics Subject Classification: 05C62. Full text: PDF