In the Nivasch probabilistic algorithm for cycle detection, pairs of function output and iteration number are stored in strictly increasing sequences in these data structures. x87 floating point architectures organize registers into a type of these structures that allow for individual access to its constituents. An algorithm that stores intermediate vertices in this data structure is used for topological sorting and for finding connected components; that algorithm is the depth-first search. The "call" one of these structures stores information about the return addresses to which each subroutine in a computer program should return control once it finishes executing. Infinite recursion of these entities may lead to their "overflow." Push and 
In the Nivasch probabilistic algorithm for cycle detection, pairs of function output and iteration number are stored in strictly increasing sequences in these data structures. x87 floating point architectures organize registers into a type of these structures that allow for individual access to its constituents. An algorithm that stores intermediate vertices in this data structure is used for topological sorting and for finding connected components; that algorithm is the depth-first search. The "call" one of these structures stores information about the return addresses to which each subroutine in a computer program should return control once it finishes executing. Infinite recursion of these entities may lead to their "overflow." Push and pop are operations on, for 10 points, what last-in first-out data structures?