Current library: Alpha v34, 4,223 checked-use theorems; Stable remains 432. Historical first admissions, original proof editions, and non-admitted aliases are preserved.
The zero window is half-open and its order hypothesis is essential. All folds retain actual beta-coded traces. These are support lemmas for the separately verified full inversion endpoint.
Exact theorem in conservative defined notation
∀ F. ∀ k. ∀ l. ∀ z. ArithTable(0,F) → Le(k,l) → SignedZeroWindow(F,k,l) → (SignedPrefixSum(F,k,z) → SignedPrefixSum(F,l,z)) ∧ (SignedPrefixSum(F,l,z) → SignedPrefixSum(F,k,z))
Every linked abbreviation expands hygienically to the identical original native formula.
Definition DAG
Actual proof prerequisites
Complete tactic proof in conservative notation
All 53 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.
Named ingredients (1)
01Fix variables and assumptionsL1–7
02Separate the logical casesL8–8
Follow the explicit conjunction, disjunction, witness, or contradiction step recorded below.
- L8
split
03Fix variables and assumptionsL9–9
Work with arbitrary variables or the premises of the current implication.
- L9
intro hs
04Establish htL10–15
Establish this local claim before using it. It is not an additional assumption. The following proof commands apply arithmetic signed sum exists.
- L10
have ht : ∃ a. SignedPrefixSum(F,l,a)Definitions: SignedPrefixSum(F,l,a)Original native command in the exact edition - L11
specialize arithmetic_signed_sum_exists (0) - L12
specialize arithmetic_signed_sum_exists (F) - L13
specialize arithmetic_signed_sum_exists (l) - L14
apply arithmetic_signed_sum_exists - L15
exact hF
05Separate the logical casesL16–16
Follow the explicit conjunction, disjunction, witness, or contradiction step recorded below.
- L16
cases ht
06Establish heL17–26
Establish this local claim before using it. It is not an additional assumption. The following proof commands apply signed prefix sum zero tail.
- L17
have he : x=z - L18
symm - L19
specialize signed_prefix_sum_zero_tail (F) - L20
specialize signed_prefix_sum_zero_tail (k) - L21
specialize signed_prefix_sum_zero_tail (l) - L22
specialize signed_prefix_sum_zero_tail (z) - L23
specialize signed_prefix_sum_zero_tail (x) - L24
apply signed_prefix_sum_zero_tail - L25
exact hkl - L26
exact hz
07Use earlier factsL27–28
08Calculate and transport equalitiesL29–30
09Use earlier factsL31–31
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L31
exact ht_witness
10Fix variables and assumptionsL32–32
Work with arbitrary variables or the premises of the current implication.
- L32
intro hs
11Establish htL33–38
Establish this local claim before using it. It is not an additional assumption. The following proof commands apply arithmetic signed sum exists.
- L33
have ht : ∃ a. SignedPrefixSum(F,k,a)Definitions: SignedPrefixSum(F,k,a)Original native command in the exact edition - L34
specialize arithmetic_signed_sum_exists (0) - L35
specialize arithmetic_signed_sum_exists (F) - L36
specialize arithmetic_signed_sum_exists (k) - L37
apply arithmetic_signed_sum_exists - L38
exact hF
12Separate the logical casesL39–39
Follow the explicit conjunction, disjunction, witness, or contradiction step recorded below.
- L39
cases ht
13Establish heL40–49
Establish this local claim before using it. It is not an additional assumption. The following proof commands apply signed prefix sum zero tail.
- L40
have he : x=z - L41
specialize signed_prefix_sum_zero_tail (F) - L42
specialize signed_prefix_sum_zero_tail (k) - L43
specialize signed_prefix_sum_zero_tail (l) - L44
specialize signed_prefix_sum_zero_tail (x) - L45
specialize signed_prefix_sum_zero_tail (z) - L46
apply signed_prefix_sum_zero_tail - L47
exact hkl - L48
exact hz - L49
exact ht_witness
14Use earlier factsL50–50
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L50
exact hs
15Calculate and transport equalitiesL51–52
16Use earlier factsL53–53
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L53
exact ht_witness
Original defined command ledger · 53 lines
- 0001
intro F - 0002
intro k - 0003
intro l - 0004
intro z - 0005
intro hF - 0006
intro hkl - 0007
intro hz - 0008
split - 0009
intro hs - 0010
have ht : ∃ a. SignedPrefixSum(F,l,a) - 0011
specialize arithmetic_signed_sum_exists (0) - 0012
specialize arithmetic_signed_sum_exists (F) - 0013
specialize arithmetic_signed_sum_exists (l) - 0014
apply arithmetic_signed_sum_exists - 0015
exact hF - 0016
cases ht - 0017
have he : x=z - 0018
symm - 0019
specialize signed_prefix_sum_zero_tail (F) - 0020
specialize signed_prefix_sum_zero_tail (k) - 0021
specialize signed_prefix_sum_zero_tail (l) - 0022
specialize signed_prefix_sum_zero_tail (z) - 0023
specialize signed_prefix_sum_zero_tail (x) - 0024
apply signed_prefix_sum_zero_tail - 0025
exact hkl - 0026
exact hz - 0027
exact hs - 0028
exact ht_witness - 0029
rewrite he at ht_witness - 0030
rewrite he at ht_witness - 0031
exact ht_witness - 0032
intro hs - 0033
have ht : ∃ a. SignedPrefixSum(F,k,a) - 0034
specialize arithmetic_signed_sum_exists (0) - 0035
specialize arithmetic_signed_sum_exists (F) - 0036
specialize arithmetic_signed_sum_exists (k) - 0037
apply arithmetic_signed_sum_exists - 0038
exact hF - 0039
cases ht - 0040
have he : x=z - 0041
specialize signed_prefix_sum_zero_tail (F) - 0042
specialize signed_prefix_sum_zero_tail (k) - 0043
specialize signed_prefix_sum_zero_tail (l) - 0044
specialize signed_prefix_sum_zero_tail (x) - 0045
specialize signed_prefix_sum_zero_tail (z) - 0046
apply signed_prefix_sum_zero_tail - 0047
exact hkl - 0048
exact hz - 0049
exact ht_witness - 0050
exact hs - 0051
rewrite he at ht_witness - 0052
rewrite he at ht_witness - 0053
exact ht_witness