How statement and proof provenance work
The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.
- Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
- AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
- AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.
These labels describe origin, not correctness: citations and verification chips remain separate evidence.
Worked coordinate criteria: four displacements classified by the future-cone inequalities
Example
Worked computation in the chart of an inertial frame of an affine Minkowski space with (Inertial frames and inertial charts of the affine Minkowski model). Put and, in order,
with the corresponding displacements and the Euclidean norm of the spatial part. Then:
(a) Future timelike. has , so lies in (Causal reachability, causal futures and pasts, causal diamonds, and reachability by future causal paths in affine Minkowski space) and confirms that is future timelike (Timelike, null, spacelike and causal vectors of a Lorentz vector space, Time orientation, future and past timelike/null/causal vectors, and the closed cones).
(b) Future null. has , so lies in but not in , and is future null.
(c) Spacelike and causally unrelated. has , so is spacelike and lies in neither nor : the pair is causally unrelated.
(d) Future timelike with past-directed companion. has and , so is future timelike; the past-directed companion is the event , whose displacement has , time component and , so lies in .
(e) The strict inequality , the equality and the reversal of the coordinate criterion therefore separate, in this single computation, the three causal characters of the displacement and the two reachability relations; the numbers are exact integers and no measurement is reported.
Facts & Assumptions
Given: An inertial frame with chart , , the events , , , , and .
Coordinate criterion: for events with , iff , and iff ; moreover iff iff the displacement satisfies (The closed future cone in inertial coordinates: description, finite sums, and the coordinate criterion for causal reachability, Causal reachability, causal futures and pasts, causal diamonds, and reachability by future causal paths in affine Minkowski space).
Diagonal form: for coordinate differences ; a displacement is timelike iff , null iff and , spacelike iff , and future-directed causal displacements are exactly the nonzero displacements with (Timelike, null, spacelike and causal vectors of a Lorentz vector space, Time orientation, future and past timelike/null/causal vectors, and the closed cones).
Verification
The four displacements are , , and by the linearity clause of the inertial chart, with spatial norms , , and ; the companion displacement is with spatial norm .
: , so by [L1] and makes future timelike by [L2]; this is (a).
: , so and by [L1], and with makes future null by [L2]; this is (b).
: gives , so is spacelike by [L2]; the criterion fails for both and , that is is false and is false, so and both fail by [L1], and the pair is causally unrelated; this is (c).
: with makes future timelike and by [L1] and [L2]. For the companion, the displacement from to is , whose reversed displacement has time component , so , that is , by [L1]; moreover with time component exhibits a past timelike displacement; this is (d).
Steps 2.1, 2.2 and 2.3 exhibit the three cases of the criterion (strict inequality, equality with positive time component, and failure in both directions), while step 2.4 exhibits a future timelike displacement together with a past-directed companion; all values are exact integers obtained from the diagonal form and the criterion, and no physical measurement or empirical claim is involved.
Depends on
The closed future cone in inertial coordinates: description, finite sums, and the coordinate criterion for causal reachability
Causal reachability, causal futures and pasts, causal diamonds, and reachability by future causal paths in affine Minkowski space
Timelike, null, spacelike and causal vectors of a Lorentz vector space
Time orientation, future and past timelike/null/causal vectors, and the closed cones
Inertial frames and inertial charts of the affine Minkowski model
Dependency tree · 2 levels
Sources
- S. M. Carroll, Lecture Notes on General Relativity, arXiv:gr-qc/9712019v1 (1997): Chapter 1 pp. 5-7 (light cones; timelike, null and spacelike separation; no coordinate-independent future for a spacelike-separated event), Chapter 4 pp. 124-127 (no signals faster than light; information flows only along timelike or null trajectories; future domain of dependence; Misner space with closed timelike curves as a warning about other topologies); PDF page = printed page + 7
- B. Crowell, Special Relativity, revision 2020-12-10 (author-published undergraduate textbook, 246 PDF pages): Section 1.3.2 pp. 22-23 (light-rectangles as causal diamonds with invariant area), Section 2.1 pp. 43-45 (the modest causality postulate P1 and the limits of a general causality principle), Section 4.7 pp. 110-113 (superluminal transmission of information, the tachyonic antitelephone attributed to Tolman, reported tachyon searches); signature (+---) converted to (-+++) and c = 1 formulas converted to x^0 = c t