DHEAP
#define HEAP0 (DHEAP - 1) /* index of first element in heap */
#define HPARENT(k) ((((k) - HEAP0 - 1) / DHEAP) + HEAP0)
ANHE *pos = heap + DHEAP * (k - HEAP0) + HEAP0 + 1;
if (expect_true (pos + DHEAP - 1 < E))