数学季刊（英文版）
數學季刊（英文版）
수학계간（영문판）
CHINESE QUARTERLY JOURNAL OF MATHEMATICS
2010年
4期
515-521
,共7页
the proper interval graph%the extended profile%tree%co-tree
The extended profile problem is to find a proper interval supergraph with the smallest possible number of edges. The problem stems from the storage and elimination techniques of a sparse symmetric matrix A in 1950's. It has important applications in numerical algebra, VLSI designs and molecular biology. A tree T is a connected acyclic graph. The complement of a tree T is called a co-tree, denoted by (T). In this paper the exact extended profile value of a cotree (T) is given.
