README

   1 This is CVC4 release version 1.5.  For build and installation notes,
   2 please see the INSTALL file included with this distribution.
   3
   4 The project leaders are Clark Barrett (Stanford University) and Cesare
   5 Tinelli (The University of Iowa).  For a full list of authors, please
   6 refer to the AUTHORS file in the source distribution.
   7
   8 CVC4 is a tool for determining the satisfiability of a first order
   9 formula modulo a first order theory (or a combination of such
  10 theories).  It is the fourth in the Cooperating Validity Checker
  11 family of tools (CVC, CVC Lite, CVC3) but does not directly
  12 incorporate code from any previous version.
  13
  14 CVC4 is intended to be an open and extensible SMT engine.  It can be
  15 used as a stand-alone tool or as a library.  It has been designed to
  16 increase the performance and reduce the memory overhead of its
  17 predecessors.  It is written entirely in C++ and is released under an
  18 open-source software license (see the file COPYING in the source
  19 distribution).
  20
  21 *** Getting started with CVC4
  22
  23 For help installing CVC4, see the INSTALL file that comes with this
  24 distribution.
  25
  26 We recommend that you visit our CVC4 tutorials online at:
  27
  28   http://cvc4.cs.stanford.edu/wiki/Tutorials
  29
  30 for help getting started using CVC4.
  31
  32 *** Contributing to the CVC4 project
  33
  34 We are always happy to hear feedback from our users:
  35
  36 * if you need help with using CVC4, please refer to
  37   http://cvc4.stanford.edu/#Technical_Support.
  38
  39 * if you need to report a bug with CVC4, or make a feature request,
  40   please visit our bugtracker at https://github.com/CVC4/CVC4/issues or
  41   write to the cvc-bugs@cs.stanford.edu mailing list.  We are very
  42   grateful for bug reports, as they help us improve CVC4, and patches
  43   are generally reviewed and accepted quickly.
  44
  45 * if you are using CVC4 in your work, or incorporating it into
  46   software of your own, we'd like to invite you to leave a description
  47   and link to your project/software on our "Third Party Applications"
  48   page at
  49   http://cvc4.cs.stanford.edu/wiki/Public:Third_Party_Applications
  50
  51 * if you are interested in contributing code (for example, a new
  52   decision procedure implementation) to the CVC4 project, please
  53   contact one of the project leaders.  We'd be happy to point you to
  54   some internals documentation to help you out.
  55
  56 Thank you for using CVC4!
  57
  58 *** The History of CVC4
  59
  60 The Cooperating Validity Checker series has a long history.  The
  61 Stanford Validity Checker (SVC) came first in 1996, incorporating
  62 theories and its own SAT solver.  Its successor, the Cooperating
  63 Validity Checker (CVC), had a more optimized internal design, produced
  64 proofs, used the Chaff SAT solver, and featured a number of usability
  65 enhancements.  Its name comes from the cooperative nature of decision
  66 procedures in Nelson-Oppen theory combination, which share amongst
  67 each other equalities between shared terms.  CVC Lite, first made
  68 available in 2003, was a rewrite of CVC that attempted to make CVC
  69 more flexible (hence the "lite") while extending the feature set: CVC
  70 Lite supported quantifiers where its predecessors did not.  CVC3 was a
  71 major overhaul of portions of CVC Lite: it added better decision
  72 procedure implementations, added support for using MiniSat in the
  73 core, and had generally better performance.
  74
  75 CVC4 is the new version, the fifth generation of this validity checker
  76 line that is now celebrating twenty-one years of heritage.  It
  77 represents a complete re-evaluation of the core architecture to be
  78 both performant and to serve as a cutting-edge research vehicle for
  79 the next several years.  Rather than taking CVC3 and redesigning
  80 problem parts, we've taken a clean-room approach, starting from
  81 scratch.  Before using any designs from CVC3, we have thoroughly
  82 scrutinized, vetted, and updated them.  Many parts of CVC4 bear only a
  83 superficial resemblance, if any, to their correspondent in CVC3.
  84
  85 However, CVC4 is fundamentally similar to CVC3 and many other modern
  86 SMT solvers: it is a DPLL(T) solver, with a SAT solver at its core and
  87 a delegation path to different decision procedure implementations,
  88 each in charge of solving formulas in some background theory.
  89
  90 The re-evaluation and ground-up rewrite was necessitated, we felt, by
  91 the performance characteristics of CVC3.  CVC3 has many useful
  92 features, but some core aspects of the design led to high memory use,
  93 and the use of heavyweight computation (where more nimble engineering
  94 approaches could suffice) makes CVC3 a much slower prover than other
  95 tools.  As these designs are central to CVC3, a new version was
  96 preferable to a selective re-engineering, which would have ballooned
  97 in short order.
  98
  99 *** For more information
 100
 101 More information about CVC4 is available at:
 102 http://cvc4.cs.stanford.edu/