Research-Stack/6-Documentation/docs/fsdu_solver_mode_atlas_2026-05-10.md
2026-05-11 22:18:31 -05:00

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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.