Invariants

• Custody separation: Borrower controls BTC. Lender controls funds.

• Atomic alignment: EVM withdrawal and BTC unlock are coupled through x for the main path and y for the fallback path. T defines the default path.

• Oracle minimization: No price feeds are required for liquidation. The Cosigner is liveness only.

• Auditability: SPV proofs, EVM events, and disclosure of x or y are publicly verifiable.

This time sequence avoids overlap with System Architecture. Architecture explains what components exist and how they are bounded. Lifecycle explains when and how they interact.