{"ast_node_type":"other","tokens":[{"end":75,"kind":"keyword","start":0,"text":"//"}]}
    //  * semi[w] is a proper ancestor of the vertex w (i.e., semi[w] != w)
    // For each vertex w (which is not the root),
    //  * idom[w] is an ancestor of semi[w] (i.e., idom[w] may equal semi[w])