FRAME A

O₀ / CAMERA
O₁ / SUBJECT

FRAME B

O₁ / SUBJECT CAMERA
O₂ / SUBJECT

same blocking.

By the time B opens,
A had already registered
the operator B requires
outside itself.

O₀ → O₁ → O₂

SCREEN DIRECTION

held.

O₂ persists through both fields.

O₂ ∈ A ∩ B

O₁ changes assignment
without changing position—

A cannot see what B already holds.

REVERSE

would require

O₀ ← O₁

current

O₀ → O₁ → O₂