Current library: Alpha v34, 4,223 checked-use theorems; Stable remains 432. Historical first admissions, original proof editions, and non-admitted aliases are preserved. Exact original first-admission records.
Exact expanded first-order arithmetic statement
forall i r. exists s. ((((exists ff_gap_mdm_lt_result_before. ff_gap_mdm_lt_result_before + S (i) = (r)) /\ s = i) \/ ((exists ff_gap_mdm_le_result_after. ff_gap_mdm_le_result_after + (r) = (i)) /\ s = S i)))Constructive proof overview
Generated structural guide
Every minor coordinate has a constructive source coordinate that skips an arbitrary deleted index.
The unchanged tactic script uses 1 declared prerequisite and contains 15 exact native proof lines.
Alpha v34 checked-use · first admitted v24 · independently kernel and Lean verified; not Stable
Proof neighborhood
Direct dependencies
le_or_lt Stable theorem; checked-use authorizedDirect dependents
Formal native tactic body
Dependencies are introduced as named hypotheses before line 1. Local theorem links identify exact declared prerequisites. This exact body belongs to a complete independently kernel-checked constructive proof bundle and has Alpha checked-use authority; it does not imply Stable membership.
Read the argument
Proof checkpoints
This is a reading aid, not a new proof or a proof-tree certificate. Checkpoint groups are consecutive commands, not inferred branch boundaries. Every step links to the preserved script.
01Fix variables and assumptionsL1–2
02Use earlier factsL3–4
03Separate the logical casesL5–5
Follow the explicit conjunction, disjunction, witness, or contradiction step recorded below.
- L5
cases le_or_lt
04Construct an explicit witnessL6–6
Supply the displayed value, then prove that it has the required property.
- L6
exists S i
05Separate the logical casesL7–8
06Use earlier factsL9–9
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L9
exact le_or_lt_left
07Calculate and transport equalitiesL10–10
Carry out the recorded arithmetic or equality steps; inspect the exact commands for their direction and premises.
- L10
refl
08Construct an explicit witnessL11–11
Supply the displayed value, then prove that it has the required property.
- L11
exists i
09Separate the logical casesL12–13
10Use earlier factsL14–14
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L14
exact le_or_lt_right
11Calculate and transport equalitiesL15–15
Carry out the recorded arithmetic or equality steps; inspect the exact commands for their direction and premises.
- L15
refl
Separate complete second-wave branches: Full T13 proof · Alpha v27.