High Integrity Systems
Author: JTC1/SC22/WG9/ARG, by Randall Brukardt, ARG Editor

Ada Reference Manual — 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 might 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.
NOTES
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1 The Valid attribute (see 13.9.2) is also useful in addressing these needs, to avoid problems that could otherwise arise from scalars that have values outside their declared range constraints.

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