In computer science, the Brodal queue is a heap/priority queue structure with very low worst case time bounds:
While having better asymptotic bounds than other priority queue structures, they are, in the words of Brodal himself, "quite complicated" and "[not] applicable in practice." Brodal and Okasaki describe a persistent (purely functional) version of Brodal queues.
Summary of running times
In the following time complexities O(f) is an asymptotic upper bound and Θ(f) is an asymptotically tight bound (see Big O notation). Function names assume a min-heap.