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
∀ w. ∀ k. ∀ k2. ∀ a. ∀ b. ∀ c. ∀ d. ∀ x. ∀ y. k = w · a + b → k2 = w · c + d → ¬k = k2 → a = c + x ∨ c = a + x → b = d + y ∨ d = b + y → Lt(0,x · x + y · y)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 w k k2 a b c d x y. k = w * a + b -> k2 = w * c + d -> ~(k = k2) -> (((a) = (c) + (x) \/ (c) = (a) + (x))) -> (((b) = (d) + (y) \/ (d) = (b) + (y))) -> (exists ftcn_strict_flat_positive. ftcn_strict_flat_positive + S (0) = (x * x + y * y))Proof neighborhood
Direct theorem prerequisites
TS001G absolute_difference_zero_forces_coordinate_equality TS001H nonzero_coordinate_pair_has_positive_square_normDirect 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 (2)
01Fix variables and assumptionsL1–10
02Fix variables and assumptionsL11–14
03Use earlier factsL15–17
04Fix variables and assumptionsL18–18
Work with arbitrary variables or the premises of the current implication.
- L18
intro hboth
05Separate the logical casesL19–19
Follow the explicit conjunction, disjunction, witness, or contradiction step recorded below.
- L19
cases hboth
06Establish hrowL20–26
Establish this local claim before using it. It is not an additional assumption. The following proof commands apply absolute difference zero forces coordinate equality.
- L20
have hrow : a = c - L21
specialize absolute_difference_zero_forces_coordinate_equality a - L22
specialize absolute_difference_zero_forces_coordinate_equality c - L23
specialize absolute_difference_zero_forces_coordinate_equality x - L24
apply absolute_difference_zero_forces_coordinate_equality - L25
exact hfirst_difference - L26
exact hboth_left
07Establish hcolumnL27–36
Establish this local claim before using it. It is not an additional assumption. The following proof commands apply absolute difference zero forces coordinate equality.
- L27
have hcolumn : b = d - L28
specialize absolute_difference_zero_forces_coordinate_equality b - L29
specialize absolute_difference_zero_forces_coordinate_equality d - L30
specialize absolute_difference_zero_forces_coordinate_equality y - L31
apply absolute_difference_zero_forces_coordinate_equality - L32
exact hsecond_difference - L33
exact hboth_right - L34
apply hdistinct - L35
trans w * a + b - L36
exact hfirst_index
08Calculate and transport equalitiesL37–41
09Use earlier factsL42–42
Instantiate or apply named facts and discharge the corresponding proof obligations.
- L42
exact hsecond_index
Original defined command ledger · 42 lines
- 0001
intro w - 0002
intro k - 0003
intro k2 - 0004
intro a - 0005
intro b - 0006
intro c - 0007
intro d - 0008
intro x - 0009
intro y - 0010
intro hfirst_index - 0011
intro hsecond_index - 0012
intro hdistinct - 0013
intro hfirst_difference - 0014
intro hsecond_difference - 0015
specialize nonzero_coordinate_pair_has_positive_square_norm x - 0016
specialize nonzero_coordinate_pair_has_positive_square_norm y - 0017
apply nonzero_coordinate_pair_has_positive_square_norm - 0018
intro hboth - 0019
cases hboth - 0020
have hrow : a = c - 0021
specialize absolute_difference_zero_forces_coordinate_equality a - 0022
specialize absolute_difference_zero_forces_coordinate_equality c - 0023
specialize absolute_difference_zero_forces_coordinate_equality x - 0024
apply absolute_difference_zero_forces_coordinate_equality - 0025
exact hfirst_difference - 0026
exact hboth_left - 0027
have hcolumn : b = d - 0028
specialize absolute_difference_zero_forces_coordinate_equality b - 0029
specialize absolute_difference_zero_forces_coordinate_equality d - 0030
specialize absolute_difference_zero_forces_coordinate_equality y - 0031
apply absolute_difference_zero_forces_coordinate_equality - 0032
exact hsecond_difference - 0033
exact hboth_right - 0034
apply hdistinct - 0035
trans w * a + b - 0036
exact hfirst_index - 0037
trans w * c + d - 0038
rewrite hrow - 0039
rewrite hcolumn - 0040
refl - 0041
symm - 0042
exact hsecond_index