3.2 KiB
FSDU Solver Mode Atlas
Status: CANDIDATE_SOLVER_BASIS
Claim boundary: this is a solver-mode atlas for the FAMM Scar Differential Update surface. It is not a claim that every algorithm has been implemented, benchmarked, or proven equivalent. It defines how traversal algorithms enter the adaptive mixture as bounded projection modes.
Theory anchor:
2-Search-Space/FAMM/docs/FSDU_theory.md
Lean anchor:
2-Search-Space/FAMM/FAMM_FSDU.lean
Core Fixture Modes
The current finite Lean fixture uses nine modes:
| Mode | Geometry | Use | Scar risk |
|---|---|---|---|
| A* | cost plus goal curvature | admissible heuristic route | stale heuristic |
| Dijkstra | isotropic cost relaxation | weighted graph baseline | expensive wavefront |
| Greedy Best-First | goal attractor collapse | fast scout | false attractor |
| BFS | expanding wavefront | unweighted reachability | frontier blow-up |
| DFS | tunneling strand | narrow/deep passage | dead-end depth |
| Bidirectional BFS | two-front closure | known start and goal | midpoint mismatch |
| Weighted A* | inflated heuristic | speed-biased route | suboptimality debt |
| Recursive Backtrack | constructive DFS with rollback | local exhaustive structure | oscillation |
| Wall Follower | boundary contour trace | embodied/local wall navigation | loop/island trap |
Extended Atlas
Additional modes can be lowered into the finite basis until they earn their own formal field.
| Family | Examples | Initial lowering |
|---|---|---|
| bounded-memory heuristic | IDA*, RBFS, SMA* | A* + DFS |
| bounded-width heuristic | Beam Search, Fringe Search | Greedy + Weighted A* |
| incremental replanning | LPA*, D*, D* Lite, ARA* | A* + scar repair sidecar |
| line-of-sight | Theta*, Lazy Theta*, Any-angle A* | A* + ray shortcut sidecar |
| grid acceleration | Jump Point Search, HPA* | A* + cached symmetry sidecar |
| weighted relaxation | Bellman-Ford, Johnson, Floyd-Warshall | Dijkstra + baseline map |
| continuous sampling | RRT, RRT*, PRM, BIT* | DFS + random scout sidecar |
| local embodied | Bug algorithms, potential fields | Wall Follower + Greedy |
| stochastic/metaheuristic | ant colony, simulated annealing, tabu, genetic | Greedy + FAMM exploration |
| game/tree search | MCTS, minimax, alpha-beta | DFS + receipt branching |
| retrieval graph | HNSW, ANN walks, learned heuristics | Greedy + Dijkstra |
Admission Rule
Each new mode needs:
selection law Q_m(v)
weight-increase alert
weight-decrease alert
scar type it tends to create
receipt shape for committed segments
negative control or failure case
If those are missing, the mode remains an atlas note rather than a formal field.
FSDU Control Law
X_t = (M_a, M_b, S_a, S_b, Theta)
DeltaS_t = S_a - S_b
commit allowed iff ||DeltaS_t|| <= epsilon
The solver atlas only changes Theta. It does not change the commitment rule.
Keeper Distinction
Classic pathfinding asks:
which algorithm finds the best path on this graph?
FSDU asks:
which mixture keeps speculative and committed scars bounded
while the graph itself may be changing?
That is the important expansion. The algorithm name is not the truth source. The replay receipt and bounded scar differential are.