Source-pinned research

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Project-declaredLean 4.31.0

Slice contains reachable

Cedar.Thm.slice_contains_reachable

Project documentation

If an entity is reachable in n steps, then it must be included in slice at n. This lemma talks about the inner slicing function, so it's possible that the entity isn't in the original entities if it's in work.

authorizationprogram verificationsemantics

Source project: Cedar Specification

Person-level attribution pending.

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Project-declaredLean 4.31.0

Type of is sound

Cedar.Thm.type_of_is_sound

Plain-language statement

If an expression is well-typed according to the typechecker, and the input environment and capabilities satisfy some invariants, then either (1) evaluation produces a value of the returned type or (2) it returns an error of type entityDoesNotExist, extensionError, or arithBoundsError. Both options are encoded in the EvaluatesTo predicate.

authorizationprogram verificationsemantics

Source project: Cedar Specification

Person-level attribution pending.

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Project-declaredLean 4.31.0

Typecheck is sound

Cedar.Thm.typecheck_is_sound

Plain-language statement

If typechecking succeeds, then for any request consistent with the schema, either (1) evaluation produces a boolean or (2) it returns an error of type entityDoesNotExist, extensionError, or arithBoundsError. Both options are encoded in the EvaluatesTo predicate. The type checker cannot protect against these errors because it has no knowledge of th...

authorizationprogram verificationsemantics

Source project: Cedar Specification

Person-level attribution pending.

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