A case for alloy annotations for efficient incremental analysis via domain specific solvers

Abstract

Alloy is a declarative modelling language based on first-order logic with sets and relations. Alloy formulas are checked for satisfiability by the fully automatic Alloy Analyzer. The analyzer, given an Alloy formula and a scope, i.e. a bound on the universe of discourse, searches for an instance i.e. a valuation to the sets and relations in the formula, such that it evaluates to true. The analyzer translates the Alloy problem to a propositional formula for which it searches a satisfying assignment via an offthe-shelf propositional satisfiability (SAT) solver. The SAT solver performs an exhaustive search and increasing the scope leads to the combinatorial explosion problem.We envision annotations, a meta-data facility used in imperative languages, as a means of augmenting Alloy models to enable more efficient analysis by specifying the priority, i.e. order of solving, of a given constraint and the slover to be used. This additional information would enable using the solutions to a particular constraint as partial solutions to the next in case constraint priority is specified and using a specific solver for reasoning about a given constraint in case a constraint solver is specified.

Annotations for Alloy: Automated Incremental Analysis Using Domain Specific Solvers

“…In a recent publication [8] we have proposed the idea of using annotations in Alloy for guiding problem partitioning. In particular, explicitly specifying the priority of a predicate as well as the solver to be used for its analysis.…”

Mixed constraints for test input generation - An initial exploration

“…A recent paper [16] presents annotations for Alloy to embed meta-data that can be used for specifying an order of solving the constraints in the model and specifying a domain specific solver to use for a given constraint, thereby enabling more efficient incremental analysis. The focus of their work is on constraints written purely in Alloy.…”