Theorem · exact resource separation

CRD-SAT-13b

Reason-path compression changes fixed first-UIP work

Exact statement

Under the fixed earliest-clause propagation policy, immutable first reasons, decisions x=0x=0 then y=0y=0, and latest-trail first-UIP analysis, FmF_m requires exactly m+1m+1 resolution pivots while GmG_m requires one. Both traces learn x∨yx\vee y, make two decisions, and encounter one conflict.

StatusProved for the stated deterministic solver interface
External reviewNo documented external or specialist review of this FPRD result is recorded.

Context

The two databases have the same semantics and every UP closure, but retain different reason paths for the same conflict.

Definitions

  • First-UIP work is the number of resolution pivots performed until one decision-level-two literal remains.
  • The fixed policy scans clauses in stored order, uses the first available unit clause as an immutable reason, and restarts the scan after each propagation.

Hypotheses and scope

  • The databases Fm,GmF_m,G_m and shortcut LL are those of CRD-SAT-13a.
  • In GmG_m, LL has highest priority; the decision prefix is x=0x=0, then y=0y=0.

Proof or evidence

In FmF_m, the reason chain is C0,X1,…,XmC_0,X_1,\ldots,X_m, so resolving the conflict clause eliminates b,am,…,a1b,a_m,\ldots,a_1 in m+1m+1 pivots. In GmG_m, the retained clause LL supplies bb directly and resolves with the conflict clause in one pivot. The packet reports 128 deterministic traces through m=64m=64.

Verification notes

The exact pivot count and common learned clause were reconstructed. The source explicitly makes clause priority and immutable reasons part of the measured interface.

Limitations

  • This is not a heuristic-independent CDCL runtime lower bound.
  • It does not prove a minimum unrestricted resolution length, proof-width separation, or conflict-count separation.
  • The acquisition cost of the shortcut is not charged.

Open work

Use CRD-SAT-14a and CRD-SAT-14b for priority-independent conclusions; retain this entry as the exact fixed-policy calculation.