src/theory/logic_info.h

   1 /*********************                                                        */
   2 /*! \file logic_info.h
   3  ** \verbatim
   4  ** Original author: Morgan Deters
   5  ** Major contributors: none
   6  ** Minor contributors (to current version): Dejan Jovanovic
   7  ** This file is part of the CVC4 project.
   8  ** Copyright (c) 2009-2013  New York University and The University of Iowa
   9  ** See the file COPYING in the top-level source directory for licensing
  10  ** information.\endverbatim
  11  **
  12  ** \brief A class giving information about a logic (group a theory modules
  13  ** and configuration information)
  14  **
  15  ** A class giving information about a logic (group of theory modules and
  16  ** configuration information).
  17  **/
  18
  19 #include "cvc4_public.h"
  20
  21 #ifndef __CVC4__LOGIC_INFO_H
  22 #define __CVC4__LOGIC_INFO_H
  23
  24 #include <string>
  25 #include <vector>
  26 #include "expr/kind.h"
  27
  28 namespace CVC4 {
  29
  30 /**
  31  * A LogicInfo instance describes a collection of theory modules and some
  32  * basic configuration about them.  Conceptually, it provides a background
  33  * context for all operations in CVC4.  Typically, when CVC4's SmtEngine
  34  * is created, it is issued a setLogic() command indicating features of the
  35  * assertions and queries to follow---for example, whether quantifiers are
  36  * used, whether integers or reals (or both) will be used, etc.
  37  *
  38  * Most places in CVC4 will only ever need to access a const reference to an
  39  * instance of this class.  Such an instance is generally set by the SmtEngine
  40  * when setLogic() is called.  However, mutating member functions are also
  41  * provided by this class so that it can be used as a more general mechanism
  42  * (e.g., for communicating to the SmtEngine which theories should be used,
  43  * rather than having to provide an SMT-LIB string).
  44  */
  45 class CVC4_PUBLIC LogicInfo {
  46   mutable std::string d_logicString; /**< an SMT-LIB-like logic string */
  47   std::vector<bool> d_theories; /**< set of active theories */
  48   size_t d_sharingTheories; /**< count of theories that need sharing */
  49
  50   // for arithmetic
  51   bool d_integers; /**< are integers used in this logic? */
  52   bool d_reals; /**< are reals used in this logic? */
  53   bool d_linear; /**< linear-only arithmetic in this logic? */
  54   bool d_differenceLogic; /**< difference-only arithmetic in this logic? */
  55   bool d_cardinalityConstraints; /**< cardinality constraints in this logic? */
  56
  57   bool d_locked; /**< is this LogicInfo instance locked (and thus immutable)? */
  58
  59   /**
  60    * Returns true iff this is a "true" theory (one that must be worried
  61    * about for sharing
  62    */
  63   static inline bool isTrueTheory(theory::TheoryId theory) {
  64     switch(theory) {
  65     case theory::THEORY_BUILTIN:
  66     case theory::THEORY_BOOL:
  67     case theory::THEORY_QUANTIFIERS:
  68       return false;
  69     default:
  70       return true;
  71     }
  72   }
  73
  74 public:
  75
  76   /**
  77    * Constructs a LogicInfo for the most general logic (quantifiers, all
  78    * background theory modules, ...).
  79    */
  80   LogicInfo();
  81
  82   /**
  83    * Construct a LogicInfo from an SMT-LIB-like logic string.
  84    * Throws an IllegalArgumentException if the logic string cannot
  85    * be interpreted.
  86    */
  87   LogicInfo(std::string logicString) throw(IllegalArgumentException);
  88
  89   /**
  90    * Construct a LogicInfo from an SMT-LIB-like logic string.
  91    * Throws an IllegalArgumentException if the logic string cannot
  92    * be interpreted.
  93    */
  94   LogicInfo(const char* logicString) throw(IllegalArgumentException);
  95
  96   // ACCESSORS
  97
  98   /**
  99    * Get an SMT-LIB-like logic string.  These are only guaranteed to
 100    * be SMT-LIB-compliant if an SMT-LIB-compliant string was used in
 101    * the constructor and no mutating functions were called.
 102    */
 103   std::string getLogicString() const;
 104
 105   /** Is sharing enabled for this logic? */
 106   bool isSharingEnabled() const {
 107     CheckArgument(d_locked, *this, "This LogicInfo isn't locked yet, and cannot be queried");
 108     return d_sharingTheories > 1;
 109   }
 110
 111   /** Is the given theory module active in this logic? */
 112   bool isTheoryEnabled(theory::TheoryId theory) const {
 113     CheckArgument(d_locked, *this, "This LogicInfo isn't locked yet, and cannot be queried");
 114     return d_theories[theory];
 115   }
 116
 117   /** Is this a quantified logic? */
 118   bool isQuantified() const {
 119     CheckArgument(d_locked, *this, "This LogicInfo isn't locked yet, and cannot be queried");
 120     return isTheoryEnabled(theory::THEORY_QUANTIFIERS);
 121   }
 122
 123   /** Is this the all-inclusive logic? */
 124   bool hasEverything() const {
 125     CheckArgument(d_locked, *this, "This LogicInfo isn't locked yet, and cannot be queried");
 126     LogicInfo everything;
 127     everything.lock();
 128     return *this == everything;
 129   }
 130
 131   /** Is this the all-exclusive logic?  (Here, that means propositional logic) */
 132   bool hasNothing() const {
 133     CheckArgument(d_locked, *this, "This LogicInfo isn't locked yet, and cannot be queried");
 134     LogicInfo nothing("");
 135     nothing.lock();
 136     return *this == nothing;
 137   }
 138
 139   /**
 140    * Is this a pure logic (only one "true" background theory).  Quantifiers
 141    * can exist in such logics though; to test for quantifier-free purity,
 142    * use "isPure(theory) && !isQuantified()".
 143    */
 144   bool isPure(theory::TheoryId theory) const {
 145     CheckArgument(d_locked, *this, "This LogicInfo isn't locked yet, and cannot be queried");
 146     // the third and fourth conjucts are really just to rule out the misleading
 147     // case where you ask isPure(THEORY_BOOL) and get true even in e.g. QF_LIA
 148     return isTheoryEnabled(theory) && !isSharingEnabled() &&
 149       ( !isTrueTheory(theory) || d_sharingTheories == 1 ) &&
 150       ( isTrueTheory(theory) || d_sharingTheories == 0 );
 151   }
 152
 153   // these are for arithmetic
 154
 155   /** Are integers in this logic? */
 156   bool areIntegersUsed() const {
 157     CheckArgument(d_locked, *this, "This LogicInfo isn't locked yet, and cannot be queried");
 158     CheckArgument(isTheoryEnabled(theory::THEORY_ARITH), *this, "Arithmetic not used in this LogicInfo; cannot ask whether integers are used");
 159     return d_integers;
 160   }
 161   /** Are reals in this logic? */
 162   bool areRealsUsed() const {
 163     CheckArgument(d_locked, *this, "This LogicInfo isn't locked yet, and cannot be queried");
 164     CheckArgument(isTheoryEnabled(theory::THEORY_ARITH), *this, "Arithmetic not used in this LogicInfo; cannot ask whether reals are used");
 165     return d_reals;
 166   }
 167   /** Does this logic only linear arithmetic? */
 168   bool isLinear() const {
 169     CheckArgument(d_locked, *this, "This LogicInfo isn't locked yet, and cannot be queried");
 170     CheckArgument(isTheoryEnabled(theory::THEORY_ARITH), *this, "Arithmetic not used in this LogicInfo; cannot ask whether it's linear");
 171     return d_linear || d_differenceLogic;
 172   }
 173   /** Does this logic only permit difference reasoning? (implies linear) */
 174   bool isDifferenceLogic() const {
 175     CheckArgument(d_locked, *this, "This LogicInfo isn't locked yet, and cannot be queried");
 176     CheckArgument(isTheoryEnabled(theory::THEORY_ARITH), *this, "Arithmetic not used in this LogicInfo; cannot ask whether it's difference logic");
 177     return d_differenceLogic;
 178   }
 179   /** Does this logic allow cardinality constraints? */
 180   bool hasCardinalityConstraints() const {
 181     CheckArgument(d_locked, *this, "This LogicInfo isn't locked yet, and cannot be queried");
 182     return d_cardinalityConstraints;
 183   }
 184
 185   // MUTATORS
 186
 187   /**
 188    * Initialize the LogicInfo with an SMT-LIB-like logic string.
 189    * Throws an IllegalArgumentException if the string can't be
 190    * interpreted.
 191    */
 192   void setLogicString(std::string logicString) throw(IllegalArgumentException);
 193
 194   /**
 195    * Enable all functionality.  All theories, plus quantifiers, will be
 196    * enabled.
 197    */
 198   void enableEverything();
 199
 200   /**
 201    * Disable all functionality.  The result will be a LogicInfo with
 202    * the BUILTIN and BOOLEAN theories enabled only ("QF_SAT").
 203    */
 204   void disableEverything();
 205
 206   /**
 207    * Enable the given theory module.
 208    */
 209   void enableTheory(theory::TheoryId theory);
 210
 211   /**
 212    * Disable the given theory module.  THEORY_BUILTIN and THEORY_BOOL cannot
 213    * be disabled (and if given here, the request will be silently ignored).
 214    */
 215   void disableTheory(theory::TheoryId theory);
 216
 217   /**
 218    * Quantifiers are a special case, since two theory modules handle them.
 219    */
 220   void enableQuantifiers() {
 221     enableTheory(theory::THEORY_QUANTIFIERS);
 222   }
 223
 224   /**
 225    * Quantifiers are a special case, since two theory modules handle them.
 226    */
 227   void disableQuantifiers() {
 228     disableTheory(theory::THEORY_QUANTIFIERS);
 229   }
 230
 231   // these are for arithmetic
 232
 233   /** Enable the use of integers in this logic. */
 234   void enableIntegers();
 235   /** Disable the use of integers in this logic. */
 236   void disableIntegers();
 237   /** Enable the use of reals in this logic. */
 238   void enableReals();
 239   /** Disable the use of reals in this logic. */
 240   void disableReals();
 241   /** Only permit difference arithmetic in this logic. */
 242   void arithOnlyDifference();
 243   /** Only permit linear arithmetic in this logic. */
 244   void arithOnlyLinear();
 245   /** Permit nonlinear arithmetic in this logic. */
 246   void arithNonLinear();
 247
 248   // LOCKING FUNCTIONALITY
 249
 250   /** Lock this LogicInfo, disabling further mutation and allowing queries */
 251   void lock() { d_locked = true; }
 252   /** Check whether this LogicInfo is locked, disallowing further mutation */
 253   bool isLocked() const { return d_locked; }
 254   /** Get a copy of this LogicInfo that is identical, but unlocked */
 255   LogicInfo getUnlockedCopy() const;
 256
 257   // COMPARISON
 258
 259   /** Are these two LogicInfos equal? */
 260   bool operator==(const LogicInfo& other) const {
 261     CheckArgument(isLocked() && other.isLocked(), *this, "This LogicInfo isn't locked yet, and cannot be queried");
 262     for(theory::TheoryId id = theory::THEORY_FIRST; id < theory::THEORY_LAST; ++id) {
 263       if(d_theories[id] != other.d_theories[id]) {
 264         return false;
 265       }
 266     }
 267     CheckArgument(d_sharingTheories == other.d_sharingTheories, *this, "LogicInfo internal inconsistency");
 268     if(isTheoryEnabled(theory::THEORY_ARITH)) {
 269       return
 270         d_integers == other.d_integers &&
 271         d_reals == other.d_reals &&
 272         d_linear == other.d_linear &&
 273         d_differenceLogic == other.d_differenceLogic;
 274     } else {
 275       return true;
 276     }
 277   }
 278   /** Are these two LogicInfos disequal? */
 279   bool operator!=(const LogicInfo& other) const {
 280     return !(*this == other);
 281   }
 282   /** Is this LogicInfo "greater than" (does it contain everything and more) the other? */
 283   bool operator>(const LogicInfo& other) const {
 284     return *this >= other && *this != other;
 285   }
 286   /** Is this LogicInfo "less than" (does it contain strictly less) the other? */
 287   bool operator<(const LogicInfo& other) const {
 288     return *this <= other && *this != other;
 289   }
 290   /** Is this LogicInfo "less than or equal" the other? */
 291   bool operator<=(const LogicInfo& other) const {
 292     CheckArgument(isLocked() && other.isLocked(), *this, "This LogicInfo isn't locked yet, and cannot be queried");
 293     for(theory::TheoryId id = theory::THEORY_FIRST; id < theory::THEORY_LAST; ++id) {
 294       if(d_theories[id] && !other.d_theories[id]) {
 295         return false;
 296       }
 297     }
 298     CheckArgument(d_sharingTheories <= other.d_sharingTheories, *this, "LogicInfo internal inconsistency");
 299     if(isTheoryEnabled(theory::THEORY_ARITH) && other.isTheoryEnabled(theory::THEORY_ARITH)) {
 300       return
 301         (!d_integers || other.d_integers) &&
 302         (!d_reals || other.d_reals) &&
 303         (d_linear || !other.d_linear) &&
 304         (d_differenceLogic || !other.d_differenceLogic);
 305     } else {
 306       return true;
 307     }
 308   }
 309   /** Is this LogicInfo "greater than or equal" the other? */
 310   bool operator>=(const LogicInfo& other) const {
 311     CheckArgument(isLocked() && other.isLocked(), *this, "This LogicInfo isn't locked yet, and cannot be queried");
 312     for(theory::TheoryId id = theory::THEORY_FIRST; id < theory::THEORY_LAST; ++id) {
 313       if(!d_theories[id] && other.d_theories[id]) {
 314         return false;
 315       }
 316     }
 317     CheckArgument(d_sharingTheories >= other.d_sharingTheories, *this, "LogicInfo internal inconsistency");
 318     if(isTheoryEnabled(theory::THEORY_ARITH) && other.isTheoryEnabled(theory::THEORY_ARITH)) {
 319       return
 320         (d_integers || !other.d_integers) &&
 321         (d_reals || !other.d_reals) &&
 322         (!d_linear || other.d_linear) &&
 323         (!d_differenceLogic || other.d_differenceLogic);
 324     } else {
 325       return true;
 326     }
 327   }
 328
 329   /** Are two LogicInfos comparable?  That is, is one of <= or > true? */
 330   bool isComparableTo(const LogicInfo& other) const {
 331     return *this <= other || *this >= other;
 332   }
 333
 334 };/* class LogicInfo */
 335
 336 std::ostream& operator<<(std::ostream& out, const LogicInfo& logic) CVC4_PUBLIC;
 337
 338 }/* CVC4 namespace */
 339
 340 #endif /* __CVC4__LOGIC_INFO_H */
 341