SMT solving

QF_BV

The quantifier-free SMT-LIB logic for fixed-width bit-vectors.

Definition

QF_BV

QF_BV contains quantifier-free formulas whose main data values are fixed-width bit-vectors.

The logic is useful for hardware, machine arithmetic, and bounded program behavior. Solvers often decide it by rewriting and bit-blasting the terms into SAT.

01

Example

An eight-bit overflow check can ask whether x + 1 is smaller than x under unsigned comparison.

02

Important distinction

QF_BV models bounded machine values, not mathematical integers of unlimited size.

After reading this article, you should be able to

  • Define QF_BV in the sense used on this site.
  • Explain why a QF_BV result may differ from the corresponding integer equation.