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.
Sets are complete characteristic-bit codes with actual finite cardinality witnesses. The proof constructs translations and the sumset; no finite-choice oracle, supplied cardinality conclusion, or unproved polynomial-method premise is used.
Exact theorem in conservative defined notation
∀ a. ∀ b. ∀ c. ∀ d. Le(a,b) → Le(c,d) → Le(a + c,b + d)
Every linked abbreviation expands hygienically to the identical original native formula.
Definition DAG
Actual proof prerequisites
Complete tactic proof in conservative notation
All 20 original proof lines are preserved. Only local proposition formulas are abbreviated; every abbreviation has an exact binder-safe expansion check. The linked exact edition contains the unchanged replay script.
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 assumptionsL1–6
02Use earlier factsL7–16
Instantiate or apply named facts and discharge the corresponding proof obligations.
Original defined command ledger · 20 lines
- 0001
intro a - 0002
intro b - 0003
intro c - 0004
intro d - 0005
intro hab - 0006
intro hcd - 0007
specialize le_trans a+c - 0008
specialize le_trans b+c - 0009
specialize le_trans b+d - 0010
apply le_trans - 0011
specialize add_le_add_right a - 0012
specialize add_le_add_right b - 0013
specialize add_le_add_right c - 0014
apply add_le_add_right - 0015
exact hab - 0016
specialize add_le_add_left c - 0017
specialize add_le_add_left d - 0018
specialize add_le_add_left b - 0019
apply add_le_add_left - 0020
exact hcd