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 expanded first-order arithmetic statement
forall a b p n. (exists ge_balance_positive_negate_intro_first ge_balance_negative_negate_intro_first. (((((a) = 2 * (ge_balance_positive_negate_intro_first) /\ (ge_balance_negative_negate_intro_first) = 0) \/ exists ge_signed_half_negate_intro_firstdecode. (((a) = 2 * ge_signed_half_negate_intro_firstdecode + 1 /\ (ge_balance_positive_negate_intro_first) = 0) /\ (ge_balance_negative_negate_intro_first) = S ge_signed_half_negate_intro_firstdecode))) /\ ((p) + ge_balance_negative_negate_intro_first = (n) + ge_balance_positive_negate_intro_first))) -> (exists ge_balance_positive_negate_intro_second ge_balance_negative_negate_intro_second. (((((b) = 2 * (ge_balance_positive_negate_intro_second) /\ (ge_balance_negative_negate_intro_second) = 0) \/ exists ge_signed_half_negate_intro_seconddecode. (((b) = 2 * ge_signed_half_negate_intro_seconddecode + 1 /\ (ge_balance_positive_negate_intro_second) = 0) /\ (ge_balance_negative_negate_intro_second) = S ge_signed_half_negate_intro_seconddecode))) /\ ((n) + ge_balance_negative_negate_intro_second = (p) + ge_balance_positive_negate_intro_second))) -> (exists mps_positive_negate_intro_result mps_negative_negate_intro_result. (((((a) = 2 * (mps_positive_negate_intro_result) /\ (mps_negative_negate_intro_result) = 0) \/ exists ge_signed_half_negate_intro_resultsource. (((a) = 2 * ge_signed_half_negate_intro_resultsource + 1 /\ (mps_positive_negate_intro_result) = 0) /\ (mps_negative_negate_intro_result) = S ge_signed_half_negate_intro_resultsource))) /\ ((((b) = 2 * (mps_negative_negate_intro_result) /\ (mps_positive_negate_intro_result) = 0) \/ exists ge_signed_half_negate_intro_resulttarget. (((b) = 2 * ge_signed_half_negate_intro_resulttarget + 1 /\ (mps_negative_negate_intro_result) = 0) /\ (mps_positive_negate_intro_result) = S ge_signed_half_negate_intro_resulttarget)))))Constructive proof overview
Generated structural guide
Opposite arbitrary component balances imply actual canonical SignedNegate, using its constructed inverse and literal functionality.
The unchanged tactic script uses 3 declared prerequisites and contains 27 exact native proof lines.
Alpha v34 checked-use · first admitted v31 · independently kernel and Lean verified; not Stable
Proof neighborhood
Direct dependencies
signed_negate_total Alpha theorem; checked-use authorized SS000F divisor_signed_balance_negate signed_balance_functional Alpha 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.
Named ingredients (1)
01Fix variables and assumptionsL1–6
02Establish hnL7–9
Establish this local claim before using it. It is not an additional assumption. The following proof commands apply signed negate total.
- L7
have hn : ∃ c. ∃ x. ∃ y. SignedDecode(a,x,y) ∧ SignedDecode(c,y,x)Definitions: SignedDecode - L8
specialize signed_negate_total (a) - L9
apply signed_negate_total
03Separate the logical casesL10–10
Follow the explicit conjunction, disjunction, witness, or contradiction step recorded below.
- L10
cases hn
04Establish heqL11–20
Establish this local claim before using it. It is not an additional assumption. The following proof commands apply signed balance functional.
- L11
have heq : x = b - L12
specialize signed_balance_functional (n) - L13
specialize signed_balance_functional (p) - L14
specialize signed_balance_functional (x) - L15
specialize signed_balance_functional (b) - L16
apply signed_balance_functional - L17
specialize divisor_signed_balance_negate (a) - L18
specialize divisor_signed_balance_negate (x) - L19
specialize divisor_signed_balance_negate (p) - L20
specialize divisor_signed_balance_negate (n)
05Use earlier factsL21–24
06Calculate and transport equalitiesL25–26
07Use earlier factsL27–27
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L27
exact hn_witness
Original exact command ledger · 27 lines
- 0001
intro a - 0002
intro b - 0003
intro p - 0004
intro n - 0005
intro ha - 0006
intro hb - 0007
have hn : exists c. (exists mps_positive_negate_intro_exists mps_negative_negate_intro_exists. (((((a) = 2 * (mps_positive_negate_intro_exists) /\ (mps_negative_negate_intro_exists) = 0) \/ exists ge_signed_half_negate_intro_existssource. (((a) = 2 * ge_signed_half_negate_intro_existssource + 1 /\ (mps_positive_negate_intro_exists) = 0) /\ (mps_negative_negate_intro_exists) = S ge_signed_half_negate_intro_existssource))) /\ ((((c) = 2 * (mps_negative_negate_intro_exists) /\ (mps_positive_negate_intro_exists) = 0) \/ exists ge_signed_half_negate_intro_existstarget. (((c) = 2 * ge_signed_half_negate_intro_existstarget + 1 /\ (mps_negative_negate_intro_exists) = 0) /\ (mps_positive_negate_intro_exists) = S ge_signed_half_negate_intro_existstarget))))) - 0008
specialize signed_negate_total (a) - 0009
apply signed_negate_total - 0010
cases hn - 0011
have heq : x = b - 0012
specialize signed_balance_functional (n) - 0013
specialize signed_balance_functional (p) - 0014
specialize signed_balance_functional (x) - 0015
specialize signed_balance_functional (b) - 0016
apply signed_balance_functional - 0017
specialize divisor_signed_balance_negate (a) - 0018
specialize divisor_signed_balance_negate (x) - 0019
specialize divisor_signed_balance_negate (p) - 0020
specialize divisor_signed_balance_negate (n) - 0021
apply divisor_signed_balance_negate - 0022
exact ha - 0023
exact hn_witness - 0024
exact hb - 0025
rewrite heq at hn_witness - 0026
rewrite heq at hn_witness - 0027
exact hn_witness