Interval --- интервал.
An interval is such an alt that its initial node belongs to each strongly connected subgraph of . The initial node of interval is also called a header node.
An interval is maximal if there is no such an interval that is a proper subfragment of .
For a given control flow graph with its initial node and a given node of , the maximal interval with the header , denoted , can be constructed by the following three rules: (1) is in ; (2) if all the predecessors of some node are in , then is in ; (3) nothing else is in .
The set of all maximal intervals of a cf-graph form a partition of the set of its nodes.
A node is a head of some maximal interval of a cf-graph if and only if either is the initial node of or is a terminal node of another maximal interval of .