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clause.hpp
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4  * Christian Schulte <schulte@gecode.org>
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7  * Christian Schulte, 2008
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33 
34 namespace Gecode { namespace Int { namespace Bool {
35 
36  /*
37  * Boolean clause propagator (disjunctive, true)
38  *
39  */
40 
41  template<class VX, class VY>
46  (home,x0[x0.size()-1],y0[y0.size()-1]), x(x0), y(y0) {
47  assert((x.size() > 0) && (y.size() > 0));
48  x.size(x.size()-1); y.size(y.size()-1);
49  }
50 
51  template<class VX, class VY>
52  PropCost
55  }
56 
57  template<class VX, class VY>
61  x.update(home,p.x);
62  y.update(home,p.y);
63  }
64 
65  template<class VX, class VY>
66  Actor*
68  {
69  int n = x.size();
70  if (n > 0) {
71  // Eliminate all zeros and find a one
72  for (int i=n; i--; )
73  if (x[i].one()) {
74  // Only keep the one
75  x[0]=x[i]; n=1; break;
76  } else if (x[i].zero()) {
77  // Eliminate the zero
78  x[i]=x[--n];
79  }
80  x.size(n);
81  }
82  }
83  {
84  int n = y.size();
85  if (n > 0) {
86  // Eliminate all zeros and find a one
87  for (int i=n; i--; )
88  if (y[i].one()) {
89  // Only keep the one
90  y[0]=y[i]; n=1; break;
91  } else if (y[i].zero()) {
92  // Eliminate the zero
93  y[i]=y[--n];
94  }
95  y.size(n);
96  }
97  }
98  if ((x.size() == 0) && (y.size() == 0))
99  return new (home) BinOrTrue<VX,VY>(home,*this,x0,x1);
100  else
101  return new (home) ClauseTrue<VX,VY>(home,*this);
102  }
103 
104  template<class VX, class VY>
105  inline ExecStatus
107  for (int i=x.size(); i--; )
108  if (x[i].one())
109  return ES_OK;
110  else if (x[i].zero())
111  x.move_lst(i);
112  if (x.size() == 0)
113  return NaryOrTrue<VY>::post(home,y);
114  for (int i=y.size(); i--; )
115  if (y[i].one())
116  return ES_OK;
117  else if (y[i].zero())
118  y.move_lst(i);
119  if (y.size() == 0)
120  return NaryOrTrue<VX>::post(home,x);
121  if ((x.size() == 1) && (y.size() == 1)) {
122  return BinOrTrue<VX,VY>::post(home,x[0],y[0]);
123  } else if (!shared(x,y)) {
124  (void) new (home) ClauseTrue(home,x,y);
125  }
126  return ES_OK;
127  }
128 
129  template<class VX, class VY>
130  forceinline size_t
133  return sizeof(*this);
134  }
135 
136  template<class VX, class VY>
139  VX& x0, ViewArray<VX>& x,
140  VY& x1, ViewArray<VY>& y) {
141  if (x0.zero()) {
142  int n = x.size();
143  for (int i=n; i--; )
144  if (x[i].one()) {
145  x.size(n);
146  return home.ES_SUBSUMED(p);
147  } else if (x[i].zero()) {
148  x[i] = x[--n];
149  } else {
150  // Rewrite if there is just one view left
151  if ((i == 0) && (y.size() == 0)) {
152  VX z = x[0]; x.size(0);
154  }
155  // Move to x0 and subscribe
156  x0=x[i]; x[i]=x[--n];
157  x.size(n);
158  x0.subscribe(home,p,PC_BOOL_VAL,false);
159  return ES_FIX;
160  }
161  // All x-views have been assigned!
162  ViewArray<VY> z(home,y.size()+1);
163  for (int i=0; i<y.size(); i++)
164  z[i]=y[i];
165  z[y.size()] = x1;
167  }
168  return ES_FIX;
169  }
170 
171  template<class VX, class VY>
172  ExecStatus
174  if (x0.one() || x1.one())
175  return home.ES_SUBSUMED(*this);
176  GECODE_ES_CHECK(resubscribe(home,*this,x0,x,x1,y));
177  GECODE_ES_CHECK(resubscribe(home,*this,x1,y,x0,x));
178  return ES_FIX;
179  }
180 
181 
182  /*
183  * Boolean clause propagator (disjunctive)
184  *
185  */
186 
187  /*
188  * Index advisors
189  *
190  */
191  template<class VX, class VY>
194  Council<Tagged>& c, bool x0)
195  : Advisor(home,p,c), x(x0) {}
196 
197  template<class VX, class VY>
200  : Advisor(home,a), x(a.x) {}
201 
202  template<class VX, class VY>
205  VX z0)
206  : Propagator(home), x(x0), y(y0), z(z0), n_zero(0), c(home) {
207  x.subscribe(home,*new (home) Tagged(home,*this,c,true));
208  y.subscribe(home,*new (home) Tagged(home,*this,c,false));
209  z.subscribe(home,*this,PC_BOOL_VAL);
210  }
211 
212  template<class VX, class VY>
215  : Propagator(home,p), n_zero(p.n_zero) {
216  x.update(home,p.x);
217  y.update(home,p.y);
218  z.update(home,p.z);
219  c.update(home,p.c);
220  }
221 
222  template<class VX>
223  forceinline void
224  eliminate_zero(ViewArray<VX>& x, int& n_zero) {
225  if (n_zero > 0) {
226  int n=x.size();
227  // Eliminate all zeros
228  for (int i=n; i--; )
229  if (x[i].zero()) {
230  x[i]=x[--n]; n_zero--;
231  }
232  x.size(n);
233  }
234  }
235 
236  template<class VX, class VY>
237  Actor*
239  eliminate_zero(x,n_zero);
240  eliminate_zero(y,n_zero);
241  return new (home) Clause<VX,VY>(home,*this);
242  }
243 
244  template<class VX, class VY>
245  inline ExecStatus
247  assert(!shared(x) && !shared(y));
248  if (z.one())
249  return ClauseTrue<VX,VY>::post(home,x,y);
250  if (z.zero()) {
251  for (int i=0; i<x.size(); i++)
252  GECODE_ME_CHECK(x[i].zero(home));
253  for (int i=0; i<y.size(); i++)
254  GECODE_ME_CHECK(y[i].zero(home));
255  return ES_OK;
256  }
257  for (int i=x.size(); i--; )
258  if (x[i].one()) {
259  GECODE_ME_CHECK(z.one_none(home));
260  return ES_OK;
261  } else if (x[i].zero()) {
262  x.move_lst(i);
263  }
264  if (x.size() == 0)
265  return NaryOr<VY,VX>::post(home,y,z);
266  for (int i=y.size(); i--; )
267  if (y[i].one()) {
268  GECODE_ME_CHECK(z.one_none(home));
269  return ES_OK;
270  } else if (y[i].zero()) {
271  y.move_lst(i);
272  }
273  if (y.size() == 0)
274  return NaryOr<VX,VX>::post(home,x,z);
275  if ((x.size() == 1) && (y.size() == 1)) {
276  return Or<VX,VY,VX>::post(home,x[0],y[0],z);
277  } else if (shared(x,y)) {
278  GECODE_ME_CHECK(z.one_none(home));
279  } else {
280  (void) new (home) Clause<VX,VY>(home,x,y,z);
281  }
282  return ES_OK;
283  }
284 
285  template<class VX, class VY>
286  PropCost
287  Clause<VX,VY>::cost(const Space&, const ModEventDelta&) const {
289  }
290 
291  template<class VX, class VY>
292  forceinline void
294  for (Advisors<Tagged> as(c); as(); ++as) {
295  if (as.advisor().x)
296  x.cancel(home,as.advisor());
297  else
298  y.cancel(home,as.advisor());
299  as.advisor().dispose(home,c);
300  }
301  c.dispose(home);
302  z.cancel(home,*this,PC_BOOL_VAL);
303  }
304 
305  template<class VX, class VY>
306  forceinline size_t
308  cancel(home);
309  (void) Propagator::dispose(home);
310  return sizeof(*this);
311  }
312 
313 
314  template<class VX, class VY>
315  ExecStatus
317  Tagged& a = static_cast<Tagged&>(_a);
318  // Decides whether the propagator must be run
319  if ((a.x && VX::zero(d)) || (!a.x && VY::zero(d)))
320  if (++n_zero < x.size() + y.size())
321  return ES_FIX;
322  return ES_NOFIX;
323  }
324 
325  template<class VX, class VY>
326  void
328  z.reschedule(home,*this,PC_BOOL_VAL);
329  if (n_zero == x.size() + y.size())
330  VX::schedule(home,*this,ME_BOOL_VAL);
331  for (int i=0; i<x.size(); i++)
332  if (x[i].one()) {
333  VX::schedule(home,*this,ME_BOOL_VAL);
334  return;
335  }
336  for (int i=0; i<y.size(); i++)
337  if (y[i].one()) {
338  VX::schedule(home,*this,ME_BOOL_VAL);
339  return;
340  }
341  }
342 
343  template<class VX, class VY>
344  ExecStatus
346  if (z.one())
347  GECODE_REWRITE(*this,(ClauseTrue<VX,VY>::post(home(*this),x,y)));
348  if (z.zero()) {
349  for (int i=0; i<x.size(); i++)
350  GECODE_ME_CHECK(x[i].zero(home));
351  for (int i=0; i<y.size(); i++)
352  GECODE_ME_CHECK(y[i].zero(home));
353  c.dispose(home);
354  } else if (n_zero == x.size() + y.size()) {
355  GECODE_ME_CHECK(z.zero_none(home));
356  c.dispose(home);
357  } else {
358  // There is at least one view which is one
359  GECODE_ME_CHECK(z.one_none(home));
360  }
361  return home.ES_SUBSUMED(*this);
362  }
363 
364 }}}
365 
366 // STATISTICS: int-prop
367 
int p
Number of positive literals for node type.
Definition: bool-expr.cpp:232
int n
Number of negative literals for node type.
Definition: bool-expr.cpp:234
Node * x
Pointer to corresponding Boolean expression node.
Definition: bool-expr.cpp:249
struct Gecode::@602::NNF::@65::@67 a
For atomic nodes.
Base-class for both propagators and branchers.
Definition: core.hpp:628
virtual size_t dispose(Space &home)
Delete actor and return its size.
Definition: core.hpp:3252
Base-class for advisors.
Definition: core.hpp:1292
Class to iterate over advisors of a council.
Definition: core.hpp:1266
Council of advisors
Definition: core.hpp:1241
Generic domain change information to be supplied to advisors.
Definition: core.hpp:204
Home class for posting propagators
Definition: core.hpp:856
Binary Boolean disjunction propagator (true)
Definition: bool.hh:237
static ExecStatus post(Home home, BVA b0, BVB b1)
Post propagator .
Definition: or.hpp:125
Boolean clause propagator (disjunctive, true)
Definition: bool.hh:547
static ExecStatus post(Home home, ViewArray< VX > &x, ViewArray< VY > &y)
Post propagator .
Definition: clause.hpp:106
ClauseTrue(Home home, ViewArray< VX > &x, ViewArray< VY > &y)
Constructor for posting.
Definition: clause.hpp:43
virtual size_t dispose(Space &home)
Delete propagator and return its size.
Definition: clause.hpp:131
virtual PropCost cost(const Space &home, const ModEventDelta &med) const
Cost function (defined as low binary)
Definition: clause.hpp:53
ViewArray< VX > x
Views not yet subscribed to.
Definition: bool.hh:552
virtual Actor * copy(Space &home)
Copy propagator during cloning.
Definition: clause.hpp:67
virtual ExecStatus propagate(Space &home, const ModEventDelta &med)
Perform propagation.
Definition: clause.hpp:173
ViewArray< VY > y
Views not yet subscribed to (origin from negative variables)
Definition: bool.hh:554
Advisors for views (tagged whether for x or y)
Definition: bool.hh:503
Tagged(Space &home, Propagator &p, Council< Tagged > &c, bool x)
Create tagged advisor.
Definition: clause.hpp:193
Boolean clause propagator (disjunctive)
Definition: bool.hh:492
virtual ExecStatus propagate(Space &home, const ModEventDelta &med)
Perform propagation.
Definition: clause.hpp:345
static ExecStatus post(Home home, ViewArray< VX > &x, ViewArray< VY > &y, VX z)
Post propagator .
Definition: clause.hpp:246
ViewArray< VX > x
Positive views.
Definition: bool.hh:495
virtual ExecStatus advise(Space &home, Advisor &a, const Delta &d)
Give advice to propagator.
Definition: clause.hpp:316
virtual void reschedule(Space &home)
Schedule function.
Definition: clause.hpp:327
int n_zero
The number of views assigned to zero in x and y.
Definition: bool.hh:501
Clause(Home home, ViewArray< VX > &x, ViewArray< VY > &y, VX z)
Constructor for posting.
Definition: clause.hpp:204
virtual size_t dispose(Space &home)
Delete propagator and return its size.
Definition: clause.hpp:307
Council< Tagged > c
The advisor council.
Definition: bool.hh:513
ViewArray< VY > y
Positive views (origin from negative variables)
Definition: bool.hh:497
virtual Actor * copy(Space &home)
Copy propagator during cloning.
Definition: clause.hpp:238
virtual PropCost cost(const Space &home, const ModEventDelta &med) const
Cost function (defined as low unary)
Definition: clause.hpp:287
void cancel(Space &home)
Cancel subscriptions.
Definition: clause.hpp:293
Boolean n-ary disjunction propagator (true)
Definition: bool.hh:393
static ExecStatus post(Home home, ViewArray< BV > &b)
Post propagator .
Definition: or.hpp:663
static ExecStatus post(Home home, ViewArray< VX > &x, VY y)
Post propagator .
Definition: or.hpp:769
static ExecStatus post(Home home, BVA b0, BVB b1, BVC b2)
Post propagator .
Definition: or.hpp:494
Mixed binary propagator.
Definition: pattern.hpp:204
Propagation cost.
Definition: core.hpp:486
static PropCost unary(PropCost::Mod m)
Single variable for modifier pcm.
Definition: core.hpp:4813
static PropCost binary(PropCost::Mod m)
Two variables for modifier pcm.
Definition: core.hpp:4809
@ LO
Cheap.
Definition: core.hpp:513
Base-class for propagators.
Definition: core.hpp:1064
Computation spaces.
Definition: core.hpp:1742
void update(Space &home, ViewArray< View > &a)
Update array to be a clone of array a.
Definition: array.hpp:1328
void subscribe(Space &home, Propagator &p, PropCond pc, bool schedule=true)
Subscribe propagator p with propagation condition pc to variable.
Definition: array.hpp:1341
int size(void) const
Return size of array (number of elements)
Definition: array.hpp:1156
ExecStatus
Definition: core.hpp:472
@ ES_OK
Execution is okay.
Definition: core.hpp:476
@ ES_FIX
Propagation has computed fixpoint.
Definition: core.hpp:477
@ ES_NOFIX
Propagation has not computed fixpoint.
Definition: core.hpp:475
Post propagator for SetVar SetOpType SetVar SetRelType SetVar z
Definition: set.hh:767
Post propagator for SetVar SetOpType SetVar y
Definition: set.hh:767
ExecStatus ES_SUBSUMED(Propagator &p)
Definition: core.hpp:3563
int ModEventDelta
Modification event deltas.
Definition: core.hpp:89
#define GECODE_ME_CHECK(me)
Check whether modification event me is failed, and forward failure.
Definition: macros.hpp:52
#define GECODE_REWRITE(prop, post)
Rewrite propagator by executing post function.
Definition: macros.hpp:116
#define GECODE_ES_CHECK(es)
Check whether execution status es is failed or subsumed, and forward failure or subsumption.
Definition: macros.hpp:91
ExecStatus resubscribe(Space &home, Propagator &p, VX &x0, ViewArray< VX > &x, VY &x1, ViewArray< VY > &y)
Definition: clause.hpp:138
void eliminate_zero(ViewArray< VX > &x, int &n_zero)
Definition: clause.hpp:224
void cancel(Space &home, Propagator &p, IntSet &y)
Definition: rel.hpp:81
bool shared(const IntSet &, VX)
Definition: view-base.hpp:118
const Gecode::ModEvent ME_BOOL_VAL
Domain operation has resulted in a value (assigned variable)
Definition: var-type.hpp:116
const Gecode::PropCond PC_BOOL_VAL
Propagate when a view becomes assigned (single value)
Definition: var-type.hpp:126
unsigned int size(I &i)
Size of all ranges of range iterator i.
Gecode::FloatVal c(-8, 8)
bool one(const Gecode::FloatValArgs &a)
Check whether has only one coefficients.
Definition: linear.cpp:46
Gecode::IntArgs i({1, 2, 3, 4})
Gecode::IntSet d(v, 7)
Single _a(2, 3)
#define forceinline
Definition: config.hpp:192