Symbolic Expressions

Write here your thoughts on the new design of the symbolic module.

Interface

These are the items exported by the symbolic module:

• SymbolicExpressionIF
• SymbolicConstantIF
• ArrayReadIF
• TupleReadIF
• ArrayWriteIF
• TupleWriteIF
• ???
• SymbolicUniverseIF

SExpression implements SymbolicExpressionIF

a canonical-form based implementation of symbolic expression

• SAndExpression extends SExpression
  • clauses: set of SOrExpression
• SOrExpression extends SExpression
  • clauses: set of SBasicExpression
• SBasicExpression extends SExpression
  • SRelationalExpression, or
  • SPrimitiveExpression, where SPrimitiveExpression has boolean type, or
  • !SPrimitiveExpression
• SRelationalExpression extends SExpression
  • e>0, e>=0, e=0, e!=0, where e is an SPolynomialExpression
• SPrimitiveExpression extends SExpression
  • X, where X is a symbolic constant
  • a[e], a is an SExpression of array type, e an SExpression of integer type
  • r.f, where r is an SExpression of tuple type and f is a nonnegative integer
• SPolynomialExpression extends SExpression
  • terms: set of SMonomialExpression
• SMonomialExpression extends SExpression
  • coefficient: Number
  • factors: set of pairs (SPrimitiveExpression, n), where n is a positive integer
• SRationalExpression extends SExpression
  • numerator, denominator: SPolynomialExpression

Numbers

Infinite-precision rational number.

SExpressionFactory

• SExpression symbolicConstant()
• SAndExpression and(Collection<SOrExpression>)
• SOrExpression or(Collection<SBasicExpression>)

etc.

SExpressionUniverse implements SymbolicUniverseIF

uses SExpressionFactory

• SExpression symbolicConstant()
• SExpression and(SExpression,SExpression);
• SExpression or(SExpression,SExpression);

etc.