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
  56   bool d_locked; /**< is this LogicInfo instance locked (and thus immutable)? */
  57
  58   /**
  59    * Returns true iff this is a "true" theory (one that must be worried
  60    * about for sharing
  61    */
  62   static inline bool isTrueTheory(theory::TheoryId theory) {
  63     switch(theory) {
  64     case theory::THEORY_BUILTIN:
  65     case theory::THEORY_BOOL:
  66     case theory::THEORY_QUANTIFIERS:
  67     case theory::THEORY_REWRITERULES:
  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) || isTheoryEnabled(theory::THEORY_REWRITERULES);
 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
 180   // MUTATORS
 181
 182   /**
 183    * Initialize the LogicInfo with an SMT-LIB-like logic string.
 184    * Throws an IllegalArgumentException if the string can't be
 185    * interpreted.
 186    */
 187   void setLogicString(std::string logicString) throw(IllegalArgumentException);
 188
 189   /**
 190    * Enable all functionality.  All theories, plus quantifiers, will be
 191    * enabled.
 192    */
 193   void enableEverything();
 194
 195   /**
 196    * Disable all functionality.  The result will be a LogicInfo with
 197    * the BUILTIN and BOOLEAN theories enabled only ("QF_SAT").
 198    */
 199   void disableEverything();
 200
 201   /**
 202    * Enable the given theory module.
 203    */
 204   void enableTheory(theory::TheoryId theory);
 205
 206   /**
 207    * Disable the given theory module.  THEORY_BUILTIN and THEORY_BOOL cannot
 208    * be disabled (and if given here, the request will be silently ignored).
 209    */
 210   void disableTheory(theory::TheoryId theory);
 211
 212   /**
 213    * Quantifiers are a special case, since two theory modules handle them.
 214    */
 215   void enableQuantifiers() {
 216     enableTheory(theory::THEORY_QUANTIFIERS);
 217     enableTheory(theory::THEORY_REWRITERULES);
 218   }
 219
 220   /**
 221    * Quantifiers are a special case, since two theory modules handle them.
 222    */
 223   void disableQuantifiers() {
 224     disableTheory(theory::THEORY_QUANTIFIERS);
 225     disableTheory(theory::THEORY_REWRITERULES);
 226   }
 227
 228   // these are for arithmetic
 229
 230   /** Enable the use of integers in this logic. */
 231   void enableIntegers();
 232   /** Disable the use of integers in this logic. */
 233   void disableIntegers();
 234   /** Enable the use of reals in this logic. */
 235   void enableReals();
 236   /** Disable the use of reals in this logic. */
 237   void disableReals();
 238   /** Only permit difference arithmetic in this logic. */
 239   void arithOnlyDifference();
 240   /** Only permit linear arithmetic in this logic. */
 241   void arithOnlyLinear();
 242   /** Permit nonlinear arithmetic in this logic. */
 243   void arithNonLinear();
 244
 245   // LOCKING FUNCTIONALITY
 246
 247   /** Lock this LogicInfo, disabling further mutation and allowing queries */
 248   void lock() { d_locked = true; }
 249   /** Check whether this LogicInfo is locked, disallowing further mutation */
 250   bool isLocked() const { return d_locked; }
 251   /** Get a copy of this LogicInfo that is identical, but unlocked */
 252   LogicInfo getUnlockedCopy() const;
 253
 254   // COMPARISON
 255
 256   /** Are these two LogicInfos equal? */
 257   bool operator==(const LogicInfo& other) const {
 258     CheckArgument(isLocked() && other.isLocked(), *this, "This LogicInfo isn't locked yet, and cannot be queried");
 259     for(theory::TheoryId id = theory::THEORY_FIRST; id < theory::THEORY_LAST; ++id) {
 260       if(d_theories[id] != other.d_theories[id]) {
 261         return false;
 262       }
 263     }
 264     CheckArgument(d_sharingTheories == other.d_sharingTheories, *this, "LogicInfo internal inconsistency");
 265     if(isTheoryEnabled(theory::THEORY_ARITH)) {
 266       return
 267         d_integers == other.d_integers &&
 268         d_reals == other.d_reals &&
 269         d_linear == other.d_linear &&
 270         d_differenceLogic == other.d_differenceLogic;
 271     } else {
 272       return true;
 273     }
 274   }
 275   /** Are these two LogicInfos disequal? */
 276   bool operator!=(const LogicInfo& other) const {
 277     return !(*this == other);
 278   }
 279   /** Is this LogicInfo "greater than" (does it contain everything and more) the other? */
 280   bool operator>(const LogicInfo& other) const {
 281     return *this >= other && *this != other;
 282   }
 283   /** Is this LogicInfo "less than" (does it contain strictly less) the other? */
 284   bool operator<(const LogicInfo& other) const {
 285     return *this <= other && *this != other;
 286   }
 287   /** Is this LogicInfo "less than or equal" the other? */
 288   bool operator<=(const LogicInfo& other) const {
 289     CheckArgument(isLocked() && other.isLocked(), *this, "This LogicInfo isn't locked yet, and cannot be queried");
 290     for(theory::TheoryId id = theory::THEORY_FIRST; id < theory::THEORY_LAST; ++id) {
 291       if(d_theories[id] && !other.d_theories[id]) {
 292         return false;
 293       }
 294     }
 295     CheckArgument(d_sharingTheories <= other.d_sharingTheories, *this, "LogicInfo internal inconsistency");
 296     if(isTheoryEnabled(theory::THEORY_ARITH) && other.isTheoryEnabled(theory::THEORY_ARITH)) {
 297       return
 298         (!d_integers || other.d_integers) &&
 299         (!d_reals || other.d_reals) &&
 300         (d_linear || !other.d_linear) &&
 301         (d_differenceLogic || !other.d_differenceLogic);
 302     } else {
 303       return true;
 304     }
 305   }
 306   /** Is this LogicInfo "greater than or equal" the other? */
 307   bool operator>=(const LogicInfo& other) const {
 308     CheckArgument(isLocked() && other.isLocked(), *this, "This LogicInfo isn't locked yet, and cannot be queried");
 309     for(theory::TheoryId id = theory::THEORY_FIRST; id < theory::THEORY_LAST; ++id) {
 310       if(!d_theories[id] && other.d_theories[id]) {
 311         return false;
 312       }
 313     }
 314     CheckArgument(d_sharingTheories >= other.d_sharingTheories, *this, "LogicInfo internal inconsistency");
 315     if(isTheoryEnabled(theory::THEORY_ARITH) && other.isTheoryEnabled(theory::THEORY_ARITH)) {
 316       return
 317         (d_integers || !other.d_integers) &&
 318         (d_reals || !other.d_reals) &&
 319         (!d_linear || other.d_linear) &&
 320         (!d_differenceLogic || other.d_differenceLogic);
 321     } else {
 322       return true;
 323     }
 324   }
 325
 326   /** Are two LogicInfos comparable?  That is, is one of <= or > true? */
 327   bool isComparableTo(const LogicInfo& other) const {
 328     return *this <= other || *this >= other;
 329   }
 330
 331 };/* class LogicInfo */
 332
 333 std::ostream& operator<<(std::ostream& out, const LogicInfo& logic) CVC4_PUBLIC;
 334
 335 }/* CVC4 namespace */
 336
 337 #endif /* __CVC4__LOGIC_INFO_H */
 338