FA-43425 / Borrow checking / Member archive

One path activates the same two-phase loan twice · case 05

One path activates the same two-phase loan twice.

Member previewVariant 5 · 3 implementations · 21 checks per implementation

Case contract

Validate reservation/activation facts of a toy two-phase mutable loan. Activation requires prior reservation, dominance and same loan identity. Reserved loan cannot be written through. Shared reads may exist during reservation but not activation. Reservation cannot cross storage death. Activation occurs at most once per path. Only compiler-generated method receiver auto-borrows may be two-phase. Argument evaluation must complete before activation. Canceled calls must release reservations. Input is a fully explicit descriptor of the stated toy IR. Return rule identifiers in declaration order; absent optional obligations use the provided neutral defaults. No rule is an assertion about a production language.

Why this case matters

A finite offline static-analysis model of ownership and borrowing; it does not execute the analyzed program.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
single-activation regression 0	`[]`	`["single-activation"]`	Failed

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