Internal set theory

Set-like behavior is reconstructed from generated divisibility and address containment, not imported from an ambient powerset universe. Membership becomes an internal divisibility/address relation; K5 blocks the diagonal move that would require a completed external totality; cardinality collapses, within the τ-internal readout, to a single countable grade _0. This gives τ enough set-theoretic grammar for later construction while refusing Cantorian infinity as primitive ontology.