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 a b c d e f g h i j k l. (((((a) + (f)) = ((e) + (b))) /\ (((c) + (h)) = ((g) + (d))))) -> (((((e) + (j)) = ((i) + (f))) /\ (((g) + (l)) = ((k) + (h))))) -> (((((a) + (j)) = ((i) + (b))) /\ (((c) + (l)) = ((k) + (d)))))Constructive proof overview
Generated structural guide
Represented Gaussian integer equality is transitive by actual signed cross-sum cancellation.
The unchanged tactic script uses 1 declared prerequisite and contains 35 exact native proof lines.
Alpha v34 checked-use · first admitted v28 · independently kernel and Lean verified; not Stable
Proof neighborhood
Direct dependencies
integer_span_pair_equal_transitive 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.
01Fix variables and assumptionsL1–10
02Fix variables and assumptionsL11–14
03Separate the logical casesL15–17
04Use earlier factsL18–27
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L18
specialize integer_span_pair_equal_transitive a - L19
specialize integer_span_pair_equal_transitive b - L20
specialize integer_span_pair_equal_transitive e - L21
specialize integer_span_pair_equal_transitive f - L22
specialize integer_span_pair_equal_transitive i - L23
specialize integer_span_pair_equal_transitive j - L24
apply integer_span_pair_equal_transitive - L25
exact hfirst_left - L26
exact hsecond_left - L27
specialize integer_span_pair_equal_transitive c
05Use earlier factsL28–35
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L28
specialize integer_span_pair_equal_transitive d - L29
specialize integer_span_pair_equal_transitive g - L30
specialize integer_span_pair_equal_transitive h - L31
specialize integer_span_pair_equal_transitive k - L32
specialize integer_span_pair_equal_transitive l - L33
apply integer_span_pair_equal_transitive - L34
exact hfirst_right - L35
exact hsecond_right
Original exact command ledger · 35 lines
- 0001
intro a - 0002
intro b - 0003
intro c - 0004
intro d - 0005
intro e - 0006
intro f - 0007
intro g - 0008
intro h - 0009
intro i - 0010
intro j - 0011
intro k - 0012
intro l - 0013
intro hfirst - 0014
intro hsecond - 0015
cases hfirst - 0016
cases hsecond - 0017
split - 0018
specialize integer_span_pair_equal_transitive a - 0019
specialize integer_span_pair_equal_transitive b - 0020
specialize integer_span_pair_equal_transitive e - 0021
specialize integer_span_pair_equal_transitive f - 0022
specialize integer_span_pair_equal_transitive i - 0023
specialize integer_span_pair_equal_transitive j - 0024
apply integer_span_pair_equal_transitive - 0025
exact hfirst_left - 0026
exact hsecond_left - 0027
specialize integer_span_pair_equal_transitive c - 0028
specialize integer_span_pair_equal_transitive d - 0029
specialize integer_span_pair_equal_transitive g - 0030
specialize integer_span_pair_equal_transitive h - 0031
specialize integer_span_pair_equal_transitive k - 0032
specialize integer_span_pair_equal_transitive l - 0033
apply integer_span_pair_equal_transitive - 0034
exact hfirst_right - 0035
exact hsecond_right