D23 Improvements to Existing Provers

Overview

The work mentioned here mainly concerns the sequent prover. All along the lifecycle of the prover, the following improvements can be achieved :

• adding new useful proof rules (to prove sequents that are hard to prove or even not provable at all)
• correcting bugs in implementations of existing proof rules
• implementing new tools to help the user do proofs
• evolving prover API to fit with the needs of prover plug-in developers

Systerel is in charge of prover improvements.

Motivations

Areas of improvement for provers can be summarized as follows:

• reducing proving time and effort
• providing the user with more efficient proving tools
  • reducing proof storage space (proof purging / simplifying)
  • ease manual proof review or reuse (prf skl view with copy paste)
• maintain consistency / coherence / ? when correcting prover implementation (versioning)
• ensure that prover modifications are well reflected by the platform

Part of implemented rules and user interface capabilities come from user feedback mainly through SourceForge feature requests. SourceForge bugs are also an important input for corrections.

Choices / Decisions

Proof storage in database ? A more generical way to contribute tactics (New tactic provider API)

Available Documentation

The following pages give useful information about prover improvements:

• Prover Rules

See http://wiki.event-b.org/index.php/Inference_Rules

See http://wiki.event-b.org/index.php/All_Rewrite_Rules

• Proof Skeleton View

See http://wiki.event-b.org/index.php/Proof_Skeleton_View

• Proof Purger

See http://wiki.event-b.org/index.php/Proof_Purger_Interface

• Prover API evolution

See http://wiki.event-b.org/index.php/New_Tactic_Providers

• Versioned Reasoners

See http://wiki.event-b.org/index.php/Versioned_Reasoners

Planning

Proof storage in database ?