SMT solving

Logic fragment

A named restriction on the terms allowed in a solver query.

Definition

Logic fragment

A logic fragment identifies a combination of theories and syntactic restrictions.

The fragment name lets users and solvers state the intended problem class. QF means quantifier-free; the remaining letters identify theories such as bit-vectors or integer arithmetic.

01

Example

QF_BV permits quantifier-free formulas over fixed-width bit-vectors.

02

Important distinction

Two fragments can share operators while requiring different decision procedures or completeness claims.

After reading this article, you should be able to

  • Define Logic fragment in the sense used on this site.
  • Decode the main parts of a common SMT-LIB logic name.