Moshe Y' Vardi

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ForSpec - Key Features

• Moshe Y. Vardi
• Rice University

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Agenda

• ForSpec Expressive power
• ForSpec Foundations
• Ease of use
• Methodology support
• Language design
• Comparison to other language candidates

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ForSpec Key Features

• Expressive Power
• Rich temporal layer LTL plus regular expressions
  Safety Liveness
• Rich layer of Boolean and arithmetic expressions
• Hardware features clocks and reset
• Hardware/Protocol modeling via assignments
• Foundations
• Well-understood computational complexity for both
  model checking and reasoning PSPACE-complete
  (wrt formula and window size)
• Uniform algorithmics (automata-based) model
  checking and reasoning,e.g., ???
• Formal semantics
• Deployed implementation

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ForSpec Key Features Cont

• Formal Semantics
• Linear time LTL plus regular expressions
• Uniformity wrt all features trace semantics (FV
  DV)
• Semantics layers basic, clocks, resets, combined
• Clean duality lemmas, e.g., !CHANGE_ON(c) f is
  equivalent to CHANGE_IF(c) !f - verified by
  theorem prover.
• Hardware Features
• Non-cumulative clocks
• Cumulative asynchronous resets
• Full integration in the semantics

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ForSpec Key Features Cont

• Ease of Use
• Intuitive semantics linear time
• ForSpec operators may be used interchangeably
  within their class, e.g., negation in formulas
• Support for modularity, reuse, customizability
  and extensibility
• Ease of expression via meta language
  (parameterized templates and blocks)
• Methodological support
• Full support for simulation
• Full support for assume-guarantee reasoning
• Session-level directives, e.g., (ASSUME,
  RESTRICT, ASSERT, )
• Full support for vacuity detection (check vacuous
  passes both for sub-formulae and for occurrences
  of sub-formulae)

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ForSpec Key Features Cont

• Assume-Guarantee
• Every property can be asserted or assumed
• Soundness and Completeness
• No need to escape the tool
• Language Design
• Rigorous design process (10 person-years)
• Compromises and trade-offs clarified by theory,
  e.g., adding negation in regular expressions
  increases the complexity dramatically
• Documented design rationale
• Ongoing development (e.g., FSMs)

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