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 g h. (((a * a + b * b + c * c + d * d) * (e * e + f * f + g * g + h * h)) + (((((a * e) * (b * f + c * g + d * h) + (b * f + c * g + d * h) * (a * e)) + ((a * f + b * e + c * h) * (d * g) + (d * g) * (a * f + b * e + c * h))) + (((a * g + c * e + d * f) * (b * h) + (b * h) * (a * g + c * e + d * f)) + ((a * h + b * g + d * e) * (c * f) + (c * f) * (a * h + b * g + d * e)))))) = (((((a * e) * (a * e) + (b * f + c * g + d * h) * (b * f + c * g + d * h)) + ((a * f + b * e + c * h) * (a * f + b * e + c * h) + (d * g) * (d * g))) + (((a * g + c * e + d * f) * (a * g + c * e + d * f) + (b * h) * (b * h)) + ((a * h + b * g + d * e) * (a * h + b * g + d * e) + (c * f) * (c * f)))))Every purple notation token opens its conservative definition. This reading surface never changes the unchanged intuitionistic kernel or confers checked-use authority.
Definitions used by this theorem
In the theorem statement
In local proof propositions
Exact expanded first-order statement
forall a b c d e f g h. (((a * a + b * b + c * c + d * d) * (e * e + f * f + g * g + h * h)) + (((((a * e) * (b * f + c * g + d * h) + (b * f + c * g + d * h) * (a * e)) + ((a * f + b * e + c * h) * (d * g) + (d * g) * (a * f + b * e + c * h))) + (((a * g + c * e + d * f) * (b * h) + (b * h) * (a * g + c * e + d * f)) + ((a * h + b * g + d * e) * (c * f) + (c * f) * (a * h + b * g + d * e)))))) = (((((a * e) * (a * e) + (b * f + c * g + d * h) * (b * f + c * g + d * h)) + ((a * f + b * e + c * h) * (a * f + b * e + c * h) + (d * g) * (d * g))) + (((a * g + c * e + d * f) * (a * g + c * e + d * f) + (b * h) * (b * h)) + ((a * h + b * g + d * e) * (a * h + b * g + d * e) + (c * f) * (c * f)))))Proof neighborhood
Direct theorem prerequisites
FS002H four_square_euler_diagonal_expansion FS002T four_square_euler_diagonal_regroup FS002V four_square_euler_cross_decomposition FS002W four_square_euler_mixed_decomposition FS002U four_square_euler_left_decompositionDirect theorem dependents
Definition-aware tactic body
Only propositions whose conservative expansion has been checked for exact first-order equivalence are compacted. Every changed line retains its immutable exact replay command.
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 (5)
01Fix variables and assumptionsL1–8
02Calculate and transport equalitiesL9–10
Carry out the recorded arithmetic or equality steps; inspect the exact commands for their direction and premises.
- L9
trans (((a * e) * (a * e) + (a * f) * (a * f) + (a * g) * (a * g) + (a * h) * (a * h)) + ((b * e) * (b * e · expand full local formula (637 characters)
trans (((a * e) * (a * e) + (a * f) * (a * f) + (a * g) * (a * g) + (a * h) * (a * h)) + ((b * e) * (b * e) + (b * f) * (b * f) + (b * g) * (b * g) + (b * h) * (b * h)) + ((c * e) * (c * e) + (c * f) * (c * f) + (c * g) * (c * g) + (c * h) * (c * h)) + ((d * e) * (d * e) + (d * f) * (d * f) + (d * g) * (d * g) + (d * h) * (d * h))) + (((((a * e) * (b * f + c * g + d * h) + (b * f + c * g + d * h) * (a * e)) + ((a * f + b * e + c * h) * (d * g) + (d * g) * (a * f + b * e + c * h))) + (((a * g + c * e + d * f) * (b * h) + (b * h) * (a * g + c * e + d * f)) + ((a * h + b * g + d * e) * (c * f) + (c * f) * (a * h + b * g + d * e))))) - L10
congr
03Use earlier factsL11–11
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L11
apply four_square_euler_diagonal_expansion
04Calculate and transport equalitiesL12–15
Carry out the recorded arithmetic or equality steps; inspect the exact commands for their direction and premises.
- L12
refl - L13
trans (((((((a * e) * (a * e)) + (((((b * f) * (b * f)) + ((c * g) * (c * g))) + ((d * h) * (d * h)))))) + · expand full local formula (707 characters)
trans (((((((a * e) * (a * e)) + (((((b * f) * (b * f)) + ((c * g) * (c * g))) + ((d * h) * (d * h)))))) + (((((((a * f) * (a * f)) + ((b * e) * (b * e))) + ((c * h) * (c * h)))) + ((d * g) * (d * g))))) + ((((((((a * g) * (a * g)) + ((c * e) * (c * e))) + ((d * f) * (d * f)))) + ((b * h) * (b * h)))) + (((((((a * h) * (a * h)) + ((b * g) * (b * g))) + ((d * e) * (d * e)))) + ((c * f) * (c * f))))))) + (((((a * e) * (b * f + c * g + d * h) + (b * f + c * g + d * h) * (a * e)) + ((a * f + b * e + c * h) * (d * g) + (d * g) * (a * f + b * e + c * h))) + (((a * g + c * e + d * f) * (b * h) + (b * h) * (a * g + c * e + d * f)) + ((a * h + b * g + d * e) * (c * f) + (c * f) * (a * h + b * g + d * e))))) - L14
congr - L15
symm
05Use earlier factsL16–16
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L16
apply four_square_euler_diagonal_regroup
06Calculate and transport equalitiesL17–20
Carry out the recorded arithmetic or equality steps; inspect the exact commands for their direction and premises.
- L17
refl - L18
trans (((((((a * e) * (a * e)) + (((((b * f) * (b * f)) + ((c * g) * (c * g))) + ((d * h) * (d * h)))))) + · expand full local formula (1,011 characters)
trans (((((((a * e) * (a * e)) + (((((b * f) * (b * f)) + ((c * g) * (c * g))) + ((d * h) * (d * h)))))) + (((((((a * f) * (a * f)) + ((b * e) * (b * e))) + ((c * h) * (c * h)))) + ((d * g) * (d * g))))) + ((((((((a * g) * (a * g)) + ((c * e) * (c * e))) + ((d * f) * (d * f)))) + ((b * h) * (b * h)))) + (((((((a * h) * (a * h)) + ((b * g) * (b * g))) + ((d * e) * (d * e)))) + ((c * f) * (c * f))))))) + ((((((((((a * e) * (b * f)) + ((b * f) * (a * e)))) + ((((a * e) * (c * g)) + ((c * g) * (a * e))))) + ((((a * e) * (d * h)) + ((d * h) * (a * e)))))) + (((((((a * f) * (d * g)) + ((d * g) * (a * f)))) + ((((b * e) * (d * g)) + ((d * g) * (b * e))))) + ((((c * h) * (d * g)) + ((d * g) * (c * h))))))) + ((((((((a * g) * (b * h)) + ((b * h) * (a * g)))) + ((((b * h) * (c * e)) + ((c * e) * (b * h))))) + ((((b * h) * (d * f)) + ((d * f) * (b * h)))))) + (((((((a * h) * (c * f)) + ((c * f) * (a * h)))) + ((((b * g) * (c * f)) + ((c * f) * (b * g))))) + ((((c * f) * (d * e)) + ((d * e) * (c * f))))))))) - L19
congr - L20
refl
07Use earlier factsL21–21
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L21
apply four_square_euler_cross_decomposition
08Calculate and transport equalitiesL22–25
Carry out the recorded arithmetic or equality steps; inspect the exact commands for their direction and premises.
- L22
trans (((((((a * e) * (a * e)) + (((((b * f) * (b * f)) + ((c * g) * (c * g))) + ((d * h) * (d * h)))))) + · expand full local formula (1,011 characters)
trans (((((((a * e) * (a * e)) + (((((b * f) * (b * f)) + ((c * g) * (c * g))) + ((d * h) * (d * h)))))) + (((((((a * f) * (a * f)) + ((b * e) * (b * e))) + ((c * h) * (c * h)))) + ((d * g) * (d * g))))) + ((((((((a * g) * (a * g)) + ((c * e) * (c * e))) + ((d * f) * (d * f)))) + ((b * h) * (b * h)))) + (((((((a * h) * (a * h)) + ((b * g) * (b * g))) + ((d * e) * (d * e)))) + ((c * f) * (c * f))))))) + ((((((((((b * f) * (c * g)) + ((c * g) * (b * f)))) + ((((b * f) * (d * h)) + ((d * h) * (b * f))))) + ((((c * g) * (d * h)) + ((d * h) * (c * g)))))) + (((((((a * f) * (b * e)) + ((b * e) * (a * f)))) + ((((a * f) * (c * h)) + ((c * h) * (a * f))))) + ((((b * e) * (c * h)) + ((c * h) * (b * e))))))) + ((((((((a * g) * (c * e)) + ((c * e) * (a * g)))) + ((((a * g) * (d * f)) + ((d * f) * (a * g))))) + ((((c * e) * (d * f)) + ((d * f) * (c * e)))))) + (((((((a * h) * (b * g)) + ((b * g) * (a * h)))) + ((((a * h) * (d * e)) + ((d * e) * (a * h))))) + ((((b * g) * (d * e)) + ((d * e) * (b * g))))))))) - L23
congr - L24
refl - L25
symm
09Use earlier factsL26–26
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L26
apply four_square_euler_mixed_decomposition
10Calculate and transport equalitiesL27–27
Carry out the recorded arithmetic or equality steps; inspect the exact commands for their direction and premises.
- L27
symm
11Use earlier factsL28–28
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L28
apply four_square_euler_left_decomposition
Original defined command ledger · 28 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
trans (((a * e) * (a * e) + (a * f) * (a * f) + (a * g) * (a * g) + (a * h) * (a * h)) + ((b * e) * (b * e) + (b * f) * (b * f) + (b * g) * (b * g) + (b * h) * (b * h)) + ((c * e) * (c * e) + (c * f) * (c * f) + (c * g) * (c * g) + (c * h) * (c * h)) + ((d * e) * (d * e) + (d * f) * (d * f) + (d * g) * (d * g) + (d * h) * (d * h))) + (((((a * e) * (b * f + c * g + d * h) + (b * f + c * g + d * h) * (a * e)) + ((a * f + b * e + c * h) * (d * g) + (d * g) * (a * f + b * e + c * h))) + (((a * g + c * e + d * f) * (b * h) + (b * h) * (a * g + c * e + d * f)) + ((a * h + b * g + d * e) * (c * f) + (c * f) * (a * h + b * g + d * e))))) - 0010
congr - 0011
apply four_square_euler_diagonal_expansion - 0012
refl - 0013
trans (((((((a * e) * (a * e)) + (((((b * f) * (b * f)) + ((c * g) * (c * g))) + ((d * h) * (d * h)))))) + (((((((a * f) * (a * f)) + ((b * e) * (b * e))) + ((c * h) * (c * h)))) + ((d * g) * (d * g))))) + ((((((((a * g) * (a * g)) + ((c * e) * (c * e))) + ((d * f) * (d * f)))) + ((b * h) * (b * h)))) + (((((((a * h) * (a * h)) + ((b * g) * (b * g))) + ((d * e) * (d * e)))) + ((c * f) * (c * f))))))) + (((((a * e) * (b * f + c * g + d * h) + (b * f + c * g + d * h) * (a * e)) + ((a * f + b * e + c * h) * (d * g) + (d * g) * (a * f + b * e + c * h))) + (((a * g + c * e + d * f) * (b * h) + (b * h) * (a * g + c * e + d * f)) + ((a * h + b * g + d * e) * (c * f) + (c * f) * (a * h + b * g + d * e))))) - 0014
congr - 0015
symm - 0016
apply four_square_euler_diagonal_regroup - 0017
refl - 0018
trans (((((((a * e) * (a * e)) + (((((b * f) * (b * f)) + ((c * g) * (c * g))) + ((d * h) * (d * h)))))) + (((((((a * f) * (a * f)) + ((b * e) * (b * e))) + ((c * h) * (c * h)))) + ((d * g) * (d * g))))) + ((((((((a * g) * (a * g)) + ((c * e) * (c * e))) + ((d * f) * (d * f)))) + ((b * h) * (b * h)))) + (((((((a * h) * (a * h)) + ((b * g) * (b * g))) + ((d * e) * (d * e)))) + ((c * f) * (c * f))))))) + ((((((((((a * e) * (b * f)) + ((b * f) * (a * e)))) + ((((a * e) * (c * g)) + ((c * g) * (a * e))))) + ((((a * e) * (d * h)) + ((d * h) * (a * e)))))) + (((((((a * f) * (d * g)) + ((d * g) * (a * f)))) + ((((b * e) * (d * g)) + ((d * g) * (b * e))))) + ((((c * h) * (d * g)) + ((d * g) * (c * h))))))) + ((((((((a * g) * (b * h)) + ((b * h) * (a * g)))) + ((((b * h) * (c * e)) + ((c * e) * (b * h))))) + ((((b * h) * (d * f)) + ((d * f) * (b * h)))))) + (((((((a * h) * (c * f)) + ((c * f) * (a * h)))) + ((((b * g) * (c * f)) + ((c * f) * (b * g))))) + ((((c * f) * (d * e)) + ((d * e) * (c * f))))))))) - 0019
congr - 0020
refl - 0021
apply four_square_euler_cross_decomposition - 0022
trans (((((((a * e) * (a * e)) + (((((b * f) * (b * f)) + ((c * g) * (c * g))) + ((d * h) * (d * h)))))) + (((((((a * f) * (a * f)) + ((b * e) * (b * e))) + ((c * h) * (c * h)))) + ((d * g) * (d * g))))) + ((((((((a * g) * (a * g)) + ((c * e) * (c * e))) + ((d * f) * (d * f)))) + ((b * h) * (b * h)))) + (((((((a * h) * (a * h)) + ((b * g) * (b * g))) + ((d * e) * (d * e)))) + ((c * f) * (c * f))))))) + ((((((((((b * f) * (c * g)) + ((c * g) * (b * f)))) + ((((b * f) * (d * h)) + ((d * h) * (b * f))))) + ((((c * g) * (d * h)) + ((d * h) * (c * g)))))) + (((((((a * f) * (b * e)) + ((b * e) * (a * f)))) + ((((a * f) * (c * h)) + ((c * h) * (a * f))))) + ((((b * e) * (c * h)) + ((c * h) * (b * e))))))) + ((((((((a * g) * (c * e)) + ((c * e) * (a * g)))) + ((((a * g) * (d * f)) + ((d * f) * (a * g))))) + ((((c * e) * (d * f)) + ((d * f) * (c * e)))))) + (((((((a * h) * (b * g)) + ((b * g) * (a * h)))) + ((((a * h) * (d * e)) + ((d * e) * (a * h))))) + ((((b * g) * (d * e)) + ((d * e) * (b * g))))))))) - 0023
congr - 0024
refl - 0025
symm - 0026
apply four_square_euler_mixed_decomposition - 0027
symm - 0028
apply four_square_euler_left_decomposition