Signpost systems and spanning trees of graphs
By a ternary system we mean an ordered pair , where is a finite nonempty set and . By a signpost system we mean a ternary system satisfying the following conditions for all : if , then and ; if , then there exists such that . In this paper, a signpost system is used as a common description of a connected graph and a spanning tree of the graph. By a ct-pair we mean an ordered pair , where is a connected graph and is a spanning tree of . If is a ct-pair, then by the guide to...