What4 is a library for representing symbolic terms and communicating with satisfiability and SMT solvers (e.g. Yices and Z3).

It was originally a part of the Crucible project, but has found use cases that are independent of its original purpose as the representation language for the Crucible symbolic simulator, and has thus been split out into a separate repository.

For an overview of What4 and how to use it, please see the package-level README.

This material is based upon work supported by the Defense Advanced Research Projects Agency (DARPA) under Contract No. HR0011-19-C-0070. The views, opinions, and/or findings expressed are those of the author(s) and should not be interpreted as representing the official views or policies of the Department of Defense or the U.S. Government.

Solver Compatibility

Feature	ABC	Boolector	CVC4	CVC5	Dreal	STP	Yices	Z3
Supported	yes	>= 3.2.0, ?	>= 1.8, ?	1.0.2	yes	>= 2.3.3, ?	2.6.x, ?	4.8.8 -- 4.8.14
goal timeouts	?	yes	yes	yes	?	yes	yes	! (4.8.11 or 4.8.12)
strings with unicode and escape codes	?	?	>= 1.8	yes	?	?	?	>= 4.8.11