CVC3: CVC3::TheoryArith Class Reference

When a term e associated with theory i occurs as a child of an expression associated with theory j, the framework calls i->addSharedTerm(e) and j->addSharedTerm(e)

Reimplemented from CVC3::Theory.

Implemented in CVC3::TheoryArithNew, CVC3::TheoryArithNew, and CVC3::TheoryArithOld.

virtual void CVC3::TheoryArith::assertFact ( const Theorem & e ) [pure virtual]

Assert a new fact to the decision procedure.

Each fact that makes it into the core framework is assigned to exactly one theory: the theory associated with that fact. assertFact is called to inform the theory that a new fact has been assigned to the theory.

Implements CVC3::Theory.

Implemented in CVC3::TheoryArithNew, CVC3::TheoryArithNew, and CVC3::TheoryArithOld.

virtual void CVC3::TheoryArith::refineCounterExample ( ) [pure virtual]

Process disequalities from the arrangement for model generation.

Reimplemented from CVC3::Theory.

Implemented in CVC3::TheoryArithNew, CVC3::TheoryArithNew, and CVC3::TheoryArithOld.

virtual void CVC3::TheoryArith::computeModelBasic ( const std::vector< Expr > & v ) [pure virtual]

Assign concrete values to basic-type variables in v.

Reimplemented from CVC3::Theory.

Implemented in CVC3::TheoryArithNew, CVC3::TheoryArithNew, and CVC3::TheoryArithOld.

virtual void CVC3::TheoryArith::computeModel	(	const Expr &	e,
		std::vector< Expr > &	vars
	)			`[pure virtual]`

Compute the value of a compound variable from the more primitive ones.

The more primitive variables for e are already assigned concrete values, and are available through getModelValue().

The new value for e must be assigned using assignValue() method.

Parameters:

	e	is the compound type expression to assign a value;
	vars	are the variables actually assigned. Normally, 'e' is the only element of vars. However, e.g. in the case of uninterpreted functions, assigning 'f' means assigning all relevant applications of 'f' to constant values (f(0), f(5), etc.). Such applications might not be known before the model is constructed (they may be of the form f(x), f(y+z), etc., where x,y,z are still unassigned).

Populating 'vars' is an opportunity for a DP to change the set of top-level "variables" to assign, if needed. In particular, it may drop 'e' from the model entirely, if it is already a concrete value by itself.

Reimplemented from CVC3::Theory.

Implemented in CVC3::TheoryArithNew, CVC3::TheoryArithNew, and CVC3::TheoryArithOld.

virtual void CVC3::TheoryArith::checkSat ( bool fullEffort ) [pure virtual]

Check for satisfiability in the theory.

Parameters:

fullEffort

when it is false, checkSat can do as much or as little work as it likes, though simple inferences and checks for consistency should be done to increase efficiency. If fullEffort is true, checkSat must check whether the set of facts given by assertFact together with the arrangement of shared terms (provided by addSharedTerm) induced by the global find database equivalence relation are satisfiable. If satisfiable, checkSat does nothing.

If satisfiability can be acheived by merging some of the shared terms, a new fact must be enqueued using enqueueFact (this fact need not be a literal). If there is no way to make things satisfiable, setInconsistent must be called.

Implements CVC3::Theory.

Implemented in CVC3::TheoryArithNew, CVC3::TheoryArithNew, and CVC3::TheoryArithOld.

virtual Theorem CVC3::TheoryArith::rewrite ( const Expr & e ) [pure virtual]

Theory-specific rewrite rules.

By default, rewrite just returns a reflexive theorem stating that the input expression is equivalent to itself. However, rewrite is allowed to return any theorem which describes how the input expression is equivalent to some new expression. rewrite should be used to perform simplifications, normalization, and any other preprocessing on theory-specific expressions that needs to be done.

Reimplemented from CVC3::Theory.

Implemented in CVC3::TheoryArithNew, CVC3::TheoryArithNew, and CVC3::TheoryArithOld.

virtual void CVC3::TheoryArith::setup ( const Expr & e ) [pure virtual]

Set up the term e for call-backs when e or its children change.

setup is called once for each expression associated with the theory. It is typically used to setup theory-specific data for an expression and to add call-back information for use with update.

See also:: update

Reimplemented from CVC3::Theory.

Implemented in CVC3::TheoryArithNew, CVC3::TheoryArithNew, and CVC3::TheoryArithOld.

virtual void CVC3::TheoryArith::update	(	const Theorem &	e,
		const Expr &	d
	)			`[pure virtual]`

Notify a theory of a new equality.

update is a call-back used by the notify mechanism of the core theory. It works as follows. When an equation t1 = t2 makes it into the core framework, the two find equivalence classes for t1 and t2 are merged. The result is that t2 is the new equivalence class representative and t1 is no longer an equivalence class representative. When this happens, the notify list of t1 is traversed. Notify list entries consist of a theory and an expression d. For each entry (i,d), i->update(e, d) is called, where e is the theorem corresponding to the equality t1=t2.

To add the entry (i,d) to a term t1's notify list, a call must be made to t1.addNotify(i,d). This is typically done in setup.

See also:: setup

Reimplemented from CVC3::Theory.

Implemented in CVC3::TheoryArithNew, CVC3::TheoryArithNew, and CVC3::TheoryArithOld.

virtual Theorem CVC3::TheoryArith::solve ( const Theorem & e ) [pure virtual]

An optional solver.

The solve method can be used to implement a Shostak-style solver. Since solvers do not in general combine, the following technique is used. One theory is designated as the primary solver (in our case, it is the theory of arithmetic). For each equation that enters the core framework, the primary solver is called to ensure that the equation is in solved form with respect to the primary theory.

After the primary solver, the solver for the theory associated with the equation is called. This solver can do whatever it likes, as long as the result is still in solved form with respect to the primary solver. This is a slight generalization of what is described in my (Clark)'s PhD thesis.

Reimplemented from CVC3::Theory.

Implemented in CVC3::TheoryArithNew, CVC3::TheoryArithNew, and CVC3::TheoryArithOld.

virtual void CVC3::TheoryArith::checkAssertEqInvariant ( const Theorem & e ) [pure virtual]

A debug check used by the primary solver.

Reimplemented from CVC3::Theory.

Implemented in CVC3::TheoryArithNew, CVC3::TheoryArithNew, and CVC3::TheoryArithOld.

virtual void CVC3::TheoryArith::checkType ( const Expr & e ) [pure virtual]

Check that e is a valid Type expr.

Reimplemented from CVC3::Theory.

Implemented in CVC3::TheoryArithNew, CVC3::TheoryArithNew, and CVC3::TheoryArithOld.

virtual void CVC3::TheoryArith::computeType ( const Expr & e ) [pure virtual]

Compute and store the type of e.

Parameters:

e

is the expression whose type is computed.

This function computes the type of the top-level operator of e, and recurses into children using getType(), if necessary.

Reimplemented from CVC3::Theory.

Implemented in CVC3::TheoryArithNew, CVC3::TheoryArithNew, and CVC3::TheoryArithOld.

virtual Type CVC3::TheoryArith::computeBaseType ( const Type & t ) [pure virtual]

Compute the base type of the top-level operator of an arbitrary type.

Reimplemented from CVC3::Theory.

Implemented in CVC3::TheoryArithNew, CVC3::TheoryArithNew, and CVC3::TheoryArithOld.

virtual void CVC3::TheoryArith::computeModelTerm	(	const Expr &	e,
		std::vector< Expr > &	v
	)			`[pure virtual]`

Add variables from 'e' to 'v' for constructing a concrete model.

If e is already of primitive type, do NOT add it to v.

Reimplemented from CVC3::Theory.

Implemented in CVC3::TheoryArithNew, CVC3::TheoryArithNew, and CVC3::TheoryArithOld.

virtual Expr CVC3::TheoryArith::computeTypePred	(	const Type &	t,
		const Expr &	e
	)			`[pure virtual]`

Theory specific computation of the subtyping predicate for type t applied to the expression e.

By default returns true. Each theory needs to compute subtype predicates for the types associated with it. So, for example, the theory of records will take a record type [# f1: T1, f2: T2 #] and an expression e and will return the subtyping predicate for e, namely: computeTypePred(T1, e.f1) AND computeTypePred(T2, e.f2)

Reimplemented from CVC3::Theory.

Implemented in CVC3::TheoryArithNew, CVC3::TheoryArithNew, and CVC3::TheoryArithOld.

virtual Expr CVC3::TheoryArith::computeTCC ( const Expr & e ) [pure virtual]

Compute and cache the TCC of e.

Parameters:

e

is an expression (term or formula). This function computes the TCC of e which is true iff the expression is defined.

This function computes the TCC or predicate of the top-level operator of e, and recurses into children using getTCC(), if necessary.

The default implementation is to compute TCCs recursively for all children, and return their conjunction.

Reimplemented from CVC3::Theory.

Implemented in CVC3::TheoryArithNew, CVC3::TheoryArithNew, and CVC3::TheoryArithOld.

virtual ExprStream& CVC3::TheoryArith::print	(	ExprStream &	os,
		const Expr &	e
	)			`[pure virtual]`

Theory-specific pretty-printing.

By default, print the top node in AST, and resume pretty-printing the children. The same call e.print(os) can be used in DP-specific printers to use AST printing for the given node. In fact, it is strongly recommended to add e.print(os) as the default for all the cases/kinds that are not handled by the particular pretty-printer.

Reimplemented from CVC3::Theory.

Implemented in CVC3::TheoryArithNew, CVC3::TheoryArithNew, and CVC3::TheoryArithOld.

virtual Expr CVC3::TheoryArith::parseExprOp ( const Expr & e ) [pure virtual]