Ada Reference Manual (Ada 2022) — Legal Information

# Annex H

## (normative)

# High Integrity Systems

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This Annex addresses requirements for high integrity systems (including safety-critical systems and security-critical systems). It provides facilities and specifies documentation requirements that relate to several needs:
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Understanding program execution;
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Reviewing object code;
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Restricting language constructs whose usage can complicate the demonstration of program correctness
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Execution understandability is supported by pragma Normalize_Scalars, and also by requirements for the implementation to document the effect of a program in the presence of a bounded error or where the language rules leave the effect unspecified.
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The pragmas Reviewable and Restrictions relate to the other requirements addressed by this Annex.
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NOTE The Valid attribute (see 13.9.2) is also useful in addressing these needs, to avoid problems that can otherwise arise from scalars that have values outside their declared range constraints.

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