dm³ 101 · Week 08 · Milestone

Milestone I — The π Constant, Closed Out

Derive the period by hand, then state precisely what is and isn’t formalized
dm³ 101 · Week 08 · Milestone
Milestone I — The π Constant, Closed Out
Course: dm³ 101  ·  Milestone  ·  Source: Book 3, “The Recurrence Ladder — From π to Hexabonacci”, Zenodo 10.5281/zenodo.19117400

Milestone task, two parts. Part 1 — by hand: starting from the contact form \(\alpha = dz - p\,dq\) on \(M = S^1 \times \mathbb{{R}}\), verify that the Reeb vector field \(R = \partial_z\) satisfies \(\alpha(R) = 1\) and \(\iota_R\, d\alpha = 0\), and show that because \(z\) is compactified as \(z \in \mathbb{{R}}/2\pi\mathbb{{Z}}\), the flow \(\phi_t(z) = z+t\) is periodic with minimal period \(T^*=2\pi\). This is exactly Theorem π.1 from Week 5 — the milestone is reproducing the three-line argument yourself, not looking it up.

Part 2 — the honesty check: write one paragraph distinguishing three separate claims about \(2\pi\) in this framework: (a) \(T^*=2\pi\) as a definitional structure field in AXLE_v6.lean — trivially true by assignment; (b) \(T^*=2\pi\) as a geometric consequence of Reeb-flow compactification — argued in prose (Book 3), reproduced by you in Part 1, not yet formalized in Lean; (c) downstream numeric facts like tau_embodiment : tau^6 = 2^6 — fully proved, 0 sorry, in Lean. Confusing these three is the single most common way a framework like this gets oversold. Keeping them separate is the actual skill this milestone is testing.

ClaimStatus
\(T^*=2\pi\) as structure dataDefinitional (trivial)
\(T^*=2\pi\) from Reeb-flow compactificationArgued in prose — not yet in Lean
\(\tau^6=2^6\), spectral period factsProved, 0 sorry

Submission: your hand derivation plus the one-paragraph status note, timestamped. Phase II is now closed — Week 9 opens Phase III with the same discipline applied to \(\varphi\).

This week’s content is grounded in Principia Orthogona, Book 3 (“The Recurrence Ladder”) and AXLE_v6.lean — theorem names and Lean identifiers above point at the actual source files.
-- dm³ 101 · Week 08 · Milestone I — π closed out
--
-- Reproduce by hand (not in Lean): Theorem π.1's three-line
-- argument (α(R)=1, ι_R dα=0, z-compactification ⇒ T*=2π).
--
-- Then classify each claim:
--   T_star := 2*Real.pi         -- definitional
--   Reeb-flow argument          -- prose-argued, not Lean-formalized
--   tau_embodiment : tau^6=2^6  -- proved, 0 sorry
--
-- Submit: hand derivation + one-paragraph status note.
example : True := trivial