re: F6 -- the human is watching their own A press, not a declared keyframe

The brief asked which of two declared events the human sees. Neither. With no
input the sweep pair enters 34 frames (f6b) and 67 frames (f6) before
ptcopyright -- 0.057 of a sweep loop in both, agreeing to 1.2% across runs
that differ 2x in frames. With A pressed during the build-in the separation
is 2 frames.

A reveals the plate and restarts both sweep leaves at t=0 in the same frame,
so a player who presses A sees them start together and reports exactly that.
The control that makes it an explanation: in the late-press run A landed
after the sweep had already started naturally and the two are 29 frames
apart -- same input, opposite result, decided by when the press falls.

Consequence for the port: do NOT start the sweep with the plate. That fits
one boot and breaks the other. The declared gate plus the snap restarting
leaves produces both observations with nothing authored.

Refutation attempt: looked for a case where the port's current behaviour
fails against these four captures; found none.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Jc4pciRArGHfxGGhEbwp5t

docs/re/f6-what-the-human-is-watching.md

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+# F6 — the human is watching **their own Ⓐ press**, not either declared event
+
+**Question:** why does a person see the glow start exactly when the plate
+appears, when the declared data starts it far earlier?
+
+**What the human looks at:** boot, and press Ⓐ early — the glow and the
+`PRESS Ⓐ` plate come up together. Then boot again and press nothing: the glow
+arrives clearly first, well before the plate.
+
+**What this does NOT cover:** the `238…250` exit ramp (already settled as an
+exit), and anything about the menu.
+
+**Instrument:** ⟨capture⟩ ×4 — two no-input controls, two with a press.
+
+## The brief asked which of two declared events this is. It is neither.
+
+| | sweep pair enters | `ptcopyright` | separation |
+|---|---|---|---|
+| `f6b` no input | f577 | f611 | **34 frames** |
+| `f6` no input | f746 | f813 | **67 frames** |
+| `f5-early` Ⓐ during build-in | f438 | f436 | **2 frames** |
+| `f5` Ⓐ *after* the sweep already started | f427 | f456 | 29 frames |
+
+Phase-free, as a fraction of the sweep's own 600-unit loop: the controls give
+**34/600 = 0.057** and **67/1168 = 0.057** — agreeing to **1.2 %** across runs
+that differ 2× in frames — against **~0.003** when Ⓐ lands early.
+
+**Ⓐ collapses the gap by a factor of ~18.** It reveals the plate and restarts
+both sweep leaves at their own `t=0` in the same frame
+([`f5-verified-with-full-quad-reader.md`](f5-verified-with-full-quad-reader.md)),
+so the two events become simultaneous *because the player caused both*.
+
+## Why the report and the data both stand
+
+The human presses Ⓐ to get through the boot — that is what a player does — and
+at that instant the plate appears and the glow restarts together. Their
+observation is accurate. It is a description of **a boot with a press in it**,
+not of the declared timeline.
+
+The last row is the check that makes this an explanation rather than a story: in
+`f5` the press landed *after* the sweep had already started on its own, and the
+two are **29 frames apart**. Same input, opposite result, decided only by when
+the press falls.
+
+## 🔴 What the port must not do
+
+**Do not start the sweep when the plate appears.** That reproduces one boot and
+breaks the other: with no input the glow genuinely precedes the plate by 0.057 of
+a sweep loop. The correct behaviour is both of the pieces already delivered —
+
+* the declared parent gate, α0 until `t=70`, full at `t=100`; **and**
+* Ⓐ restarting both leaves at `t=0` as it advances the shared clock.
+
+Together those produce the human's observation *and* the no-input one, with
+nothing authored.
+
+## Refutation attempt
+
+I tried to find a case where the port's current behaviour (declared gate + snap
+restarting leaves) fails against these captures, and **could not**. All four runs
+are consistent with it. Recorded as an attempt that did not land.
+
+## Not settled
+
+* The per-cycle phase fit for the post-wrap decomposition.
+* Wrap-to-wrap sweep period: still one wrap per capture.