Program structure tree
Encyclopedia
A program structure tree (PST) is a hierarchical diagram that displays the nesting relationship of single-entry single-exit
(SESE) regions, showing the organization of a computer program
. Nodes in this tree represent SESE regions of the program, while edges represent nesting
regions. The PST is defined for all control flow graphs.
Single-entry single-exit
In graph theory, a single-entry single-exit region in a given graph is an ordered edge pair of distinct control flow edges a and b where:#a dominates b#b postdominates a...
(SESE) regions, showing the organization of a computer program
Computer program
A computer program is a sequence of instructions written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute...
. Nodes in this tree represent SESE regions of the program, while edges represent nesting
Nesting (computing)
In computing science and informatics, the word nesting may denote several different constructions and activities where information is organized in layers or objects contain other similar objects. The rather general term is thus used in quite specific ways for various situations and concepts...
regions. The PST is defined for all control flow graphs.