1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
|
/**************************************************************/
/* ********************************************************** */
/* * * */
/* * INTERFACE FOR ALL ORDERING IMPLEMENTATIONS * */
/* * * */
/* * $Module: ORDER * */
/* * * */
/* * Copyright (C) 1997, 1998, 1999, 2000, 2001 * */
/* * MPI fuer Informatik * */
/* * * */
/* * This program is free software; you can redistribute * */
/* * it and/or modify it under the terms of the GNU * */
/* * General Public License as published by the Free * */
/* * Software Foundation; either version 2 of the License, * */
/* * or (at your option) any later version. * */
/* * * */
/* * This program is distributed in the hope that it will * */
/* * be useful, but WITHOUT ANY WARRANTY; without even * */
/* * the implied warranty of MERCHANTABILITY or FITNESS * */
/* * FOR A PARTICULAR PURPOSE. See the GNU General Public * */
/* * License for more details. * */
/* * * */
/* * You should have received a copy of the GNU General * */
/* * Public License along with this program; if not, write * */
/* * to the Free Software Foundation, Inc., 59 Temple * */
/* * Place, Suite 330, Boston, MA 02111-1307 USA * */
/* * * */
/* * * */
/* $Revision: 21527 $ * */
/* $State$ * */
/* $Date: 2005-04-24 21:10:28 -0700 (Sun, 24 Apr 2005) $ * */
/* $Author: duraid $ * */
/* * * */
/* * Contact: * */
/* * Christoph Weidenbach * */
/* * MPI fuer Informatik * */
/* * Stuhlsatzenhausweg 85 * */
/* * 66123 Saarbruecken * */
/* * Email: weidenb@mpi-sb.mpg.de * */
/* * Germany * */
/* * * */
/* ********************************************************** */
/**************************************************************/
/* $RCSfile$ */
#include "flags.h"
#include "order.h"
#include "kbo.h"
#include "rpos.h"
#include "symbol.h"
NAT ord_VARCOUNT[symbol__MAXSTANDARDVAR][2];
PRECEDENCE ord_PRECEDENCE;
static ord_RESULT ord_CheckDomPred(TERM T1, TERM T2, PRECEDENCE P)
/**************************************************************
INPUT: Two terms and a precedence.
RETURNS: An ordering result with respect to a possible domination
of leading predicates in <T1> or <T2>.
***************************************************************/
{
if ((term_IsAtom(T1) && symbol_HasProperty(term_TopSymbol(T1), DOMPRED)) ||
(term_IsAtom(T2) && symbol_HasProperty(term_TopSymbol(T2), DOMPRED))) {
if (term_IsAtom(T1)) {
if (term_IsAtom(T2)) {
if (symbol_HasProperty(term_TopSymbol(T1), DOMPRED) &&
(!symbol_HasProperty(term_TopSymbol(T2), DOMPRED) ||
symbol_PrecedenceGreater(P,term_TopSymbol(T1),term_TopSymbol(T2))))
return ord_GREATER_THAN;
if (!symbol_HasProperty(term_TopSymbol(T1), DOMPRED) ||
term_TopSymbol(T1) != term_TopSymbol(T2))
return ord_SMALLER_THAN;
/* If the top symbols are equal, do the normal comparison */
} else {
/* T1 is an atom, T2 is not, so T1 is greater */
return ord_GREATER_THAN;
}
} else {
/* T1 is not an atom, so T2 must be an atom */
return ord_SMALLER_THAN;
}
}
return ord_UNCOMPARABLE;
}
ord_RESULT ord_Compare(TERM T1, TERM T2, FLAGSTORE FlagStore, PRECEDENCE P)
/**************************************************************
INPUT:
RETURNS:
***************************************************************/
{
ord_RESULT Aux;
#ifdef CHECK
if (fol_IsEquality(T1) || fol_IsEquality(T2)) {
misc_StartErrorReport();
misc_ErrorReport("\n In ord_Compare:");
misc_ErrorReport("\n Illegal input. One input term is an equality.");
misc_FinishErrorReport();
}
#endif
Aux = ord_CheckDomPred(T1, T2, P);
if (Aux != ord_UNCOMPARABLE)
return Aux;
else {
ord_PRECEDENCE = P;
switch(flag_GetFlagValue(FlagStore, flag_ORD)) {
case flag_ORDKBO: return kbo_Compare(T1, T2); break;
case flag_ORDRPOS: return rpos_Compare(T1, T2); break;
default:
misc_StartErrorReport();
misc_ErrorReport("\n In ord_Compare:");
misc_ErrorReport("\n Illegal ordering type.");
misc_FinishErrorReport();
}
}
return ord_UNCOMPARABLE;
}
BOOL ord_CompareEqual(TERM T1, TERM T2, FLAGSTORE Flags)
/**************************************************************
INPUT: Two terms and a flag store.
RETURNS: TRUE, iff the two terms are equal with respect to the
reduction ordering selected by the 'flag_ORD' flag.
***************************************************************/
{
switch(flag_GetFlagValue(Flags, flag_ORD)) {
case flag_ORDKBO: return term_Equal(T1, T2); break;
case flag_ORDRPOS: return rpos_Equal(T1, T2); break;
default:
misc_StartErrorReport();
misc_ErrorReport("\n In ord_Compare: Illegal ordering type.");
misc_FinishErrorReport();
return FALSE; /* unreachable code ... */
}
}
ord_RESULT ord_ContCompare(CONTEXT C1, TERM T1, CONTEXT C2, TERM T2,
FLAGSTORE FlagStore, PRECEDENCE P)
{
ord_RESULT Aux;
#ifdef CHECK
if (fol_IsEquality(T1) || fol_IsEquality(T2)) {
misc_StartErrorReport();
misc_ErrorReport("\n In ord_ContCompare:");
misc_ErrorReport("\n Illegal input. One input term is an equality.");
misc_FinishErrorReport();
}
#endif
Aux = ord_CheckDomPred(T1, T2, P);
if (Aux != ord_UNCOMPARABLE)
return Aux;
else {
ord_PRECEDENCE = P;
switch(flag_GetFlagValue(FlagStore, flag_ORD)) {
case flag_ORDKBO: return kbo_ContCompare(C1, T1, C2, T2); break;
case flag_ORDRPOS: return rpos_ContCompare(C1, T1, C2, T2); break;
default:
misc_StartErrorReport();
misc_ErrorReport("\n In ord_ContCompare:");
misc_ErrorReport("\n Illegal ordering type.");
misc_FinishErrorReport();
}
}
return ord_UNCOMPARABLE;
}
BOOL ord_ContGreater(CONTEXT C1, TERM T1, CONTEXT C2, TERM T2,
FLAGSTORE FlagStore, PRECEDENCE P)
{
ord_RESULT Aux;
#ifdef CHECK
if (fol_IsEquality(T1) || fol_IsEquality(T2)) {
misc_StartErrorReport();
misc_ErrorReport("\n In ord_ContGreater:");
misc_ErrorReport("\n Illegal input. One input term is an equality.");
misc_FinishErrorReport();
}
#endif
Aux = ord_CheckDomPred(T1, T2, P);
if (Aux != ord_UNCOMPARABLE)
return (Aux == ord_GREATER_THAN);
else {
ord_PRECEDENCE = P;
switch(flag_GetFlagValue(FlagStore, flag_ORD)) {
case flag_ORDKBO: return kbo_ContGreater(C1, T1, C2, T2); break;
case flag_ORDRPOS: return rpos_ContGreater(C1, T1, C2, T2); break;
default:
misc_StartErrorReport();
misc_ErrorReport("\n In ord_ContGreater:");
misc_ErrorReport("\n Illegal ordering type.");
misc_FinishErrorReport();
}
}
return FALSE; /* This line is never reached ... */
}
ord_RESULT ord_Not(ord_RESULT Result)
/**************************************************************
INPUT: An ord_RESULT
RETURNS: The negation with respect to argument switching.
***************************************************************/
{
if (Result == ord_UNCOMPARABLE || Result == ord_EQUAL)
return Result;
if (Result == ord_GREATER_THAN)
return ord_SMALLER_THAN;
return ord_GREATER_THAN;
}
void ord_Print(ord_RESULT Result)
/**************************************************************
INPUT: An ord_Result.
RETURNS: None, prints the Result as a string to stdout.
***************************************************************/
{
switch(Result) {
case ord_UNCOMPARABLE: fputs(" uncomparable ",stdout); break;
case ord_EQUAL: fputs(" equal ",stdout); break;
case ord_GREATER_THAN: fputs(" greater than ",stdout); break;
case ord_SMALLER_THAN: fputs(" smaller than ",stdout); break;
default: fputs(" Nonsense! ",stdout);
}
}
ord_RESULT ord_LiteralCompare(TERM Lit1, BOOL Orient1, TERM Lit2, BOOL Orient2,
BOOL Check, FLAGSTORE FlagStore,
PRECEDENCE Precedence)
/*********************************************************
INPUT: Two term literals and two flags indicating whether these
two literals are oriented equalities.
Additionally a check flag that indicates whether
the orientation flags are sufficient or necessary and sufficient:
If Check=TRUE then if flag is FALSE it is interpreted that it is not
known whether the (possible) equation can be oriented oriented.
However, if flag is TRUE we assume that it is oriented.
A flag store.
A precedence.
RETURNS: The result if these literals are compared with
respect to the ordering. Dependent on their sign, the literals
are compared as multiset of their topsymbol terms,
where any literal is considered to be an equation
and non equational literals are considered to be
equations with the artificial, non-existent, minimal
constant tt.
EFFECT: The arguments of the literals are possibly, destructively flipped.
**********************************************************/
{
ord_RESULT result,auxResult,AuxRl1r2,AuxRr1r2,AuxRr1l2,Comp1,Comp2;
BOOL pos1,pos2;
pos1 = pos2 = TRUE;
Comp1 = Comp2 = result = ord_UNCOMPARABLE;
if (symbol_Equal(term_TopSymbol(Lit1),fol_Not())) {
Lit1 = term_FirstArgument(Lit1);
pos1 = FALSE;
}
if (symbol_Equal(term_TopSymbol(Lit2),fol_Not())) {
Lit2 = term_FirstArgument(Lit2);
pos2 = FALSE;
}
if (fol_IsEquality(Lit1)) { /* Real equation */
if (fol_IsEquality(Lit2)) {
TERM l1,r1,l2,r2,aux;
l1 = term_FirstArgument(Lit1);
r1 = term_SecondArgument(Lit1);
l2 = term_FirstArgument(Lit2);
r2 = term_SecondArgument(Lit2);
if (Orient1 ||
(Check &&
((Comp1 = ord_Compare(l1,r1,FlagStore,Precedence)) == ord_GREATER_THAN ||
Comp1 == ord_SMALLER_THAN))) {
if (Comp1 == ord_SMALLER_THAN) {
aux = l1; l1 = r1; r1 = aux;
}
if (Orient2 ||
(Check &&
((Comp2 = ord_Compare(l2,r2,FlagStore,Precedence))==ord_GREATER_THAN ||
Comp2 == ord_SMALLER_THAN))) {
/* Both equations are oriented */
if (Comp2 == ord_SMALLER_THAN) {
aux = l2; l2 = r2; r2 = aux;
}
result = ord_Compare(l1,l2, FlagStore, Precedence);
if (result == ord_EQUAL) {
if (pos1) {
if (pos2)
return ord_Compare(r1,r2, FlagStore, Precedence);
else
return ord_SMALLER_THAN;
}
else
if (pos2)
return ord_GREATER_THAN;
else
return ord_Compare(r1,r2, FlagStore, Precedence);
}
return result;
}
else { /* Lit2 is not oriented equation */
if (term_Equal(l1,l2)) {
result = ord_Compare(r1,r2, FlagStore, Precedence);
if (result == ord_EQUAL) {
if (pos1 && !pos2)
return ord_SMALLER_THAN;
else
if (!pos1 && pos2)
return ord_GREATER_THAN;
}
return result;
}
if (term_Equal(l1,r2)) {
result = ord_Compare(r1,l2, FlagStore, Precedence);
if (result == ord_EQUAL) {
if (pos1 && !pos2)
return ord_SMALLER_THAN;
else
if (!pos1 && pos2)
return ord_GREATER_THAN;
}
return result;
}
result = ord_Compare(l1,l2, FlagStore, Precedence);
AuxRl1r2 = ord_Compare(l1,r2, FlagStore, Precedence);
if (result == AuxRl1r2)
return result;
AuxRr1r2 = ord_Compare(r1,r2, FlagStore, Precedence);
if (result == AuxRr1r2)
return result;
if (AuxRl1r2 == AuxRr1r2 && AuxRl1r2 == ord_SMALLER_THAN)
return ord_SMALLER_THAN;
AuxRr1l2 = ord_Compare(r1,l2, FlagStore, Precedence);
if (result == AuxRr1l2 && result == ord_SMALLER_THAN)
return ord_SMALLER_THAN;
return ord_UNCOMPARABLE;
}
}
else /* Lit1 is unorientable equation */
if (Orient2 ||
(Check &&
((Comp2 = ord_Compare(term_FirstArgument(Lit2),
term_SecondArgument(Lit2),
FlagStore, Precedence) == ord_GREATER_THAN) ||
Comp2 == ord_SMALLER_THAN))) { /* Lit2 is orientable equation */
if (Comp2 == ord_SMALLER_THAN) {
aux = l2; l2 = r2; r2 = aux;
}
if (term_Equal(l1,l2)) {
result = ord_Compare(r1,r2, FlagStore, Precedence);
if (result == ord_EQUAL) {
if (pos1 && !pos2)
return ord_SMALLER_THAN;
else
if (!pos1 && pos2)
return ord_GREATER_THAN;
}
return result;
}
if (term_Equal(r1,l2)) {
result = ord_Compare(l1,r2, FlagStore, Precedence);
if (result == ord_EQUAL) {
if (pos1 && !pos2)
return ord_SMALLER_THAN;
else
if (!pos1 && pos2)
return ord_GREATER_THAN;
}
return result;
}
result = ord_Compare(l1,l2, FlagStore, Precedence);
AuxRr1l2 = ord_Compare(r1,l2, FlagStore, Precedence);
if (result == AuxRr1l2)
return result;
AuxRr1r2 = ord_Compare(r1,r2, FlagStore, Precedence);
if (result == AuxRr1r2)
return result;
if (AuxRr1l2 == AuxRr1r2 && AuxRr1l2 == ord_GREATER_THAN)
return ord_GREATER_THAN;
AuxRl1r2 = ord_Compare(l1,r2, FlagStore, Precedence);
if (result == AuxRl1r2 && result == ord_GREATER_THAN)
return ord_GREATER_THAN;
return ord_UNCOMPARABLE;
}
else { /* Both literals are unorientable equations */
if (term_Equal(l1,l2)) {
result = ord_Compare(r1,r2, FlagStore, Precedence);
if (result == ord_EQUAL) {
if (pos1 && !pos2)
return ord_SMALLER_THAN;
else if (!pos1 && pos2)
return ord_GREATER_THAN;
}
return result;
}
if (term_Equal(r1,l2)) {
result = ord_Compare(l1,r2, FlagStore, Precedence);
if (result == ord_EQUAL) {
if (pos1 && !pos2)
return ord_SMALLER_THAN;
else if (!pos1 && pos2)
return ord_GREATER_THAN;
}
return result;
}
if (term_Equal(l1,r2)) {
result = ord_Compare(r1,l2, FlagStore, Precedence);
if (result == ord_EQUAL) {
if (pos1 && !pos2)
return ord_SMALLER_THAN;
else if (!pos1 && pos2)
return ord_GREATER_THAN;
}
return result;
}
if (term_Equal(r1,r2)) {
result = ord_Compare(l1,l2, FlagStore, Precedence);
if (result == ord_EQUAL) {
if (pos1 && !pos2)
return ord_SMALLER_THAN;
else if (!pos1 && pos2)
return ord_GREATER_THAN;
}
return result;
}
result = ord_Compare(l1,l2, FlagStore, Precedence);
if (result == ord_UNCOMPARABLE) {
result = ord_Compare(l1,r2, FlagStore, Precedence);
if (result == ord_UNCOMPARABLE) {
if (ord_Compare(r1,l2, FlagStore, Precedence) == ord_GREATER_THAN &&
ord_Compare(r1,r2, FlagStore, Precedence) == ord_GREATER_THAN)
return ord_GREATER_THAN;
return ord_UNCOMPARABLE;
}
if (result == ord_GREATER_THAN) {
if (ord_Compare(r1,l2, FlagStore, Precedence) == ord_GREATER_THAN)
return ord_GREATER_THAN;
return ord_UNCOMPARABLE;
}
if (result == ord_SMALLER_THAN) {
if (ord_Compare(r1,l2, FlagStore, Precedence) == ord_SMALLER_THAN ||
ord_Compare(r1,r2, FlagStore, Precedence) == ord_SMALLER_THAN)
return ord_SMALLER_THAN;
return ord_UNCOMPARABLE;
}
}
if (result == ord_GREATER_THAN) {
if ((result = ord_Compare(l1,r2,FlagStore,Precedence)) == ord_GREATER_THAN ||
(auxResult = ord_Compare(r1,r2,FlagStore,Precedence)) == ord_GREATER_THAN)
return ord_GREATER_THAN;
if (result == ord_UNCOMPARABLE || auxResult == ord_UNCOMPARABLE)
return ord_UNCOMPARABLE;
return ord_SMALLER_THAN;
}
if (result == ord_SMALLER_THAN) {
if ((result = ord_Compare(r1,l2,FlagStore,Precedence)) == ord_SMALLER_THAN ||
(auxResult = ord_Compare(r1,r2,FlagStore,Precedence)) == ord_SMALLER_THAN)
return ord_SMALLER_THAN;
if (result == ord_UNCOMPARABLE || auxResult == ord_UNCOMPARABLE)
return ord_UNCOMPARABLE;
return ord_GREATER_THAN;
}
}
}
else {/* Second Atom is not an equation */
/* They can't be equal ! */
result = ord_Compare(term_FirstArgument(Lit1),Lit2,FlagStore,Precedence);
if (!Orient1 && result != ord_GREATER_THAN) {
auxResult = ord_Compare(term_SecondArgument(Lit1),Lit2,FlagStore,Precedence);
if (auxResult == ord_GREATER_THAN)
result = ord_GREATER_THAN;
else if (result != auxResult)
result = ord_UNCOMPARABLE;
}
}
}
else /* First Atom is not an equation */
/* They can't be equal ! */
if (fol_IsEquality(Lit2)) {
result = ord_Compare(Lit1,term_FirstArgument(Lit2), FlagStore, Precedence);
if (!Orient2 && result != ord_SMALLER_THAN) {
auxResult = ord_Compare(Lit1,term_SecondArgument(Lit2),FlagStore,Precedence);
if (auxResult == ord_SMALLER_THAN)
result = ord_SMALLER_THAN;
else if (result != auxResult)
result = ord_UNCOMPARABLE;
}
} else { /* None of the atoms is an equation */
result = ord_Compare(Lit1,Lit2, FlagStore, Precedence);
if (result == ord_EQUAL) {
if (pos1 && !pos2)
result = ord_SMALLER_THAN;
else if (!pos1 && pos2)
result = ord_GREATER_THAN;
}
}
return result;
}
|
