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.
Statement with defined notation
forall a b c d e f. ((a + b) + (c + d)) + (e + f) = (a + e) + ((b + c) + (d + f))Every purple notation token opens its conservative definition. Expanding the displayed statement recovers the exact first-order Peano-arithmetic formula checked by the unchanged kernel.
Definitions used by this theorem
In the theorem statement
0 occurrences
In local proof propositions
0 occurrences
Exact expanded native-PA statement
forall a b c d e f. ((a + b) + (c + d)) + (e + f) = (a + e) + ((b + c) + (d + f))Proof neighborhood
Direct theorem prerequisites
Direct theorem dependents
Definition-aware tactic body
Only local propositions introduced by have or suffices are compacted. Every changed line has an exact-AST conservative-expansion receipt; the kernel still receives the immutable original tactic 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 (2)
01Fix variables and assumptionsL1–6
02Calculate and transport equalitiesL7–8
03Use earlier factsL9–9
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L9
apply add_assoc
04Calculate and transport equalitiesL10–11
05Use earlier factsL12–12
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L12
apply add_assoc
06Calculate and transport equalitiesL13–15
07Use earlier factsL16–16
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L16
apply add_assoc
08Calculate and transport equalitiesL17–21
09Use earlier factsL22–22
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L22
apply add_assoc
10Calculate and transport equalitiesL23–29
11Use earlier factsL30–30
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L30
apply bertrand_add_swap_nested
12Calculate and transport equalitiesL31–35
13Use earlier factsL36–36
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L36
apply bertrand_add_swap_nested
14Calculate and transport equalitiesL37–39
15Use earlier factsL40–40
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L40
apply bertrand_add_swap_nested
16Calculate and transport equalitiesL41–42
17Use earlier factsL43–43
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L43
apply add_assoc
18Calculate and transport equalitiesL44–47
19Use earlier factsL48–48
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L48
apply add_assoc
20Calculate and transport equalitiesL49–49
Carry out the recorded arithmetic or equality steps; inspect the exact commands for their direction and premises.
- L49
refl
Original defined command ledger · 49 lines
- 0001
intro a - 0002
intro b - 0003
intro c - 0004
intro d - 0005
intro e - 0006
intro f - 0007
trans (a + (b + (c + d))) + (e + f) - 0008
congr - 0009
apply add_assoc - 0010
refl - 0011
trans a + ((b + (c + d)) + (e + f)) - 0012
apply add_assoc - 0013
trans a + (b + ((c + d) + (e + f))) - 0014
congr - 0015
refl - 0016
apply add_assoc - 0017
trans a + (b + (c + (d + (e + f)))) - 0018
congr - 0019
refl - 0020
congr - 0021
refl - 0022
apply add_assoc - 0023
trans a + (b + (c + (e + (d + f)))) - 0024
congr - 0025
refl - 0026
congr - 0027
refl - 0028
congr - 0029
refl - 0030
apply bertrand_add_swap_nested - 0031
trans a + (b + (e + (c + (d + f)))) - 0032
congr - 0033
refl - 0034
congr - 0035
refl - 0036
apply bertrand_add_swap_nested - 0037
trans a + (e + (b + (c + (d + f)))) - 0038
congr - 0039
refl - 0040
apply bertrand_add_swap_nested - 0041
trans (a + e) + (b + (c + (d + f))) - 0042
symm - 0043
apply add_assoc - 0044
trans (a + e) + ((b + c) + (d + f)) - 0045
congr - 0046
refl - 0047
symm - 0048
apply add_assoc - 0049
refl