+ /**
+ * @brief Identifies the next event from the unfolding of the concurrent system
+ * that should next be explored as an extension of a configuration with
+ * enabled events `enC`
+ *
+ * @param A The set of events `A` maintained by the UDPOR algorithm to help
+ * determine how events should be selected. See the original paper [1] for more details
+ *
+ * @param enC The set `enC` of enabled events from the extension set `exC` used
+ * by the UDPOR algorithm to select new events to search. See the original
+ * paper [1] for more details
+ */
+ UnfoldingEvent* select_next_unfolding_event(const EventSet& A, const EventSet& enC);
+
+ /**
+ * @brief Computes the sets `ex(C)` and `en(C)` of the given configuration
+ * `C` as an incremental computation from the the previous computation of `ex(C)`
+ *
+ * A central component to UDPOR is the computation of the set `ex(C)`. The
+ * extension set `ex(C)` of a configuration `C` is defined as the set of events
+ * outside of `C` whose full dependency chain is contained in `C` (see [1]
+ * for more details).
+ *
+ * In general, computing `ex(C)` is very expensive. In paper [3], The Anh Pham
+ * shows a method of incremental computation of the set `ex(C)` under the
+ * conclusions afforded under the computation model in consideration, of which
+ * SimGrid is apart, which allow for `ex(C)` to be computed much more efficiently.
+ * Intuitively, the idea is to take advantage of the fact that you can avoid a lot
+ * of repeated computation by exploiting the aforementioned properties (in [3]) in
+ * what is akin to a dynamic programming optimization. See [3] for more details
+ *
+ * @param C the configuration based on which the two sets `ex(C)` and `en(C)` are
+ * computed
+ * @param stateC the state of the program after having executed C (viz. `state(C)`)
+ * @param prev_exC the previous value of `ex(C)`, viz. that which was computed for
+ * the configuration `C' := C - {e}`
+ * @returns the extension set `ex(C)` of `C`
+ */
+ EventSet compute_exC(const Configuration& C, const State& stateC, const EventSet& prev_exC);
+ EventSet compute_enC(const Configuration& C, const EventSet& exC) const;
+
+ /**
+ *
+ */
+ void move_to_stateCe(State* stateC, UnfoldingEvent* e);
+
+ /**
+ * @brief Creates a new snapshot of the state of the application
+ * as it currently looks
+ */
+ std::unique_ptr<State> record_current_state();
+
+ /**
+ * @brief Move the application side into the state at the top of the
+ * state stack provided
+ *
+ * As UDPOR performs its search, it moves the application-side along with
+ * it so that the application is always providing the checker with
+ * the correct information about what each actor is running (and whether
+ * those actors are enabled) at the state reached by the configuration it
+ * decides to search.
+ *
+ * When UDPOR decides to "backtrack" (e.g. after reaching a configuration
+ * whose en(C) is empty), before it attempts to continue the search by taking
+ * a different path from a configuration it visited in the past, it must ensure
+ * that the application-side has moved back into `state(C)`.
+ *
+ * The search may have moved the application arbitrarily deep into its execution,
+ * and the search may backtrack arbitrarily closer to the beginning of the execution.
+ * The UDPOR implementation in SimGrid ensures that the stack is updated appropriately,
+ * but the process must still be regenerated.
+ */
+ void restore_program_state_with_current_stack();
+
+ /**
+ * @brief Perform the functionality of the `Remove(e, C, D)` function in [1]
+ */
+ void clean_up_explore(const UnfoldingEvent* e, const Configuration& C, const EventSet& D);
+};
+} // namespace simgrid::mc::udpor