| 1 | /* This file is part of the project "Hilbert II" - http://www.qedeq.org |
| 2 | * |
| 3 | * Copyright 2000-2014, Michael Meyling <mime@qedeq.org>. |
| 4 | * |
| 5 | * "Hilbert II" is free software; you can redistribute |
| 6 | * it and/or modify it under the terms of the GNU General Public |
| 7 | * License as published by the Free Software Foundation; either |
| 8 | * version 2 of the License, or (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | */ |
| 15 | |
| 16 | package org.qedeq.kernel.bo.logic.proof.finder; |
| 17 | |
| 18 | import java.util.ArrayList; |
| 19 | import java.util.Iterator; |
| 20 | import java.util.List; |
| 21 | import java.util.SortedSet; |
| 22 | import java.util.TreeSet; |
| 23 | |
| 24 | import org.qedeq.base.io.Parameters; |
| 25 | import org.qedeq.base.utility.StringUtility; |
| 26 | import org.qedeq.kernel.bo.common.Element2Utf8; |
| 27 | import org.qedeq.kernel.bo.log.ModuleLogListener; |
| 28 | import org.qedeq.kernel.bo.logic.common.FormulaUtility; |
| 29 | import org.qedeq.kernel.bo.logic.common.Operators; |
| 30 | import org.qedeq.kernel.bo.logic.proof.common.ProofException; |
| 31 | import org.qedeq.kernel.bo.logic.proof.common.ProofFinder; |
| 32 | import org.qedeq.kernel.bo.logic.proof.common.ProofFoundException; |
| 33 | import org.qedeq.kernel.bo.logic.proof.common.ProofNotFoundException; |
| 34 | import org.qedeq.kernel.se.base.list.Element; |
| 35 | import org.qedeq.kernel.se.base.list.ElementList; |
| 36 | import org.qedeq.kernel.se.base.module.Add; |
| 37 | import org.qedeq.kernel.se.base.module.FormalProofLineList; |
| 38 | import org.qedeq.kernel.se.base.module.ModusPonens; |
| 39 | import org.qedeq.kernel.se.base.module.Reason; |
| 40 | import org.qedeq.kernel.se.common.ModuleContext; |
| 41 | import org.qedeq.kernel.se.dto.list.DefaultElementList; |
| 42 | import org.qedeq.kernel.se.dto.list.ElementSet; |
| 43 | import org.qedeq.kernel.se.visitor.InterruptException; |
| 44 | |
| 45 | |
| 46 | /** |
| 47 | * Find basic proofs for formulas. |
| 48 | * |
| 49 | * @author Michael Meyling |
| 50 | */ |
| 51 | public class ProofFinderImpl implements ProofFinder { |
| 52 | |
| 53 | /** List of proof lines. */ |
| 54 | private List lines; |
| 55 | |
| 56 | /** List of reasons. */ |
| 57 | private List reasons; |
| 58 | |
| 59 | /** Set of all predicate variables that occur in this proof anywhere. */ |
| 60 | private ElementSet allPredVars; |
| 61 | |
| 62 | /** Set of all substitution formulas we try. */ |
| 63 | private ElementSet partGoalFormulas; |
| 64 | |
| 65 | /** Below this number MP was tried. */ |
| 66 | private int mpLast; |
| 67 | |
| 68 | /** Goal to prove. */ |
| 69 | private Element goalFormula; |
| 70 | |
| 71 | /** Number of extra propositional variables. */ |
| 72 | private int extraVars; |
| 73 | |
| 74 | /** Skip this number list of formulas. */ |
| 75 | private String skipFormulas; |
| 76 | |
| 77 | /** Log proof line after this number of new proof lines. */ |
| 78 | private int logFrequence; |
| 79 | |
| 80 | /** Ordered substitution methods that implement {@link Substitute}. */ |
| 81 | private SortedSet substitutionMethods; |
| 82 | |
| 83 | /** Maximum number of proof lines. */ |
| 84 | private int maxProofLines; |
| 85 | |
| 86 | /** Here are we. */ |
| 87 | private ModuleContext context; |
| 88 | |
| 89 | /** Log progress herein. */ |
| 90 | private ModuleLogListener log; |
| 91 | |
| 92 | /** Transformer to get UTF-8 out of formulas. */ |
| 93 | private Element2Utf8 trans; |
| 94 | |
| 95 | /** |
| 96 | * Constructor. |
| 97 | */ |
| 98 | public ProofFinderImpl() { |
| 99 | // nothing to do |
| 100 | } |
| 101 | |
| 102 | public void findProof(final Element formula, |
| 103 | final FormalProofLineList proof, final ModuleContext context, |
| 104 | final Parameters parameters, final ModuleLogListener log, final Element2Utf8 trans) |
| 105 | throws ProofException, InterruptException { |
| 106 | this.goalFormula = formula; |
| 107 | this.context = new ModuleContext(context); // use copy constructor to fix it |
| 108 | this.log = log; |
| 109 | this.trans = trans; |
| 110 | substitutionMethods = new TreeSet(); |
| 111 | extraVars = parameters.getInt("extraVars"); |
| 112 | maxProofLines = parameters.getInt("maximumProofLines"); |
| 113 | skipFormulas = parameters.getString("skipFormulas").trim(); |
| 114 | if (skipFormulas.length() > 0) { |
| 115 | log.logMessageState("skipping the following formula numbers: " + skipFormulas); |
| 116 | skipFormulas = "," + StringUtility.replace(skipFormulas, " ", "") + ","; |
| 117 | } |
| 118 | // TODO 20110606 m31: check that we have the correct format (e.g. only "," as separator) |
| 119 | System.out.println("maximumProofLines = " + maxProofLines); |
| 120 | int weight = 0; |
| 121 | weight = parameters.getInt("propositionVariableWeight"); |
| 122 | if (weight > 0) { |
| 123 | substitutionMethods.add(new SubstituteBase(weight, parameters.getInt("propositionVariableOrder")) { |
| 124 | public void substitute(final int i) throws ProofException { |
| 125 | substituteByPropositionVariables(i); |
| 126 | } |
| 127 | }); |
| 128 | } |
| 129 | weight = parameters.getInt("partFormulaWeight"); |
| 130 | if (weight > 0) { |
| 131 | substitutionMethods.add(new SubstituteBase(weight, parameters.getInt("partFormulaOrder")) { |
| 132 | public void substitute(final int i) throws ProofException { |
| 133 | substitutePartGoalFormulas(i); |
| 134 | } |
| 135 | }); |
| 136 | } |
| 137 | weight = parameters.getInt("disjunctionWeight"); |
| 138 | if (weight > 0) { |
| 139 | substitutionMethods.add(new SubstituteBase(weight, parameters.getInt("disjunctionOrder")) { |
| 140 | public void substitute(final int i) throws ProofException { |
| 141 | substituteDisjunction(i); |
| 142 | } |
| 143 | }); |
| 144 | } |
| 145 | weight = parameters.getInt("implicationWeight"); |
| 146 | if (weight > 0) { |
| 147 | substitutionMethods.add(new SubstituteBase(weight, parameters.getInt("implicationOrder")) { |
| 148 | public void substitute(final int i) throws ProofException { |
| 149 | substituteImplication(i); |
| 150 | } |
| 151 | }); |
| 152 | } |
| 153 | weight = parameters.getInt("negationWeight"); |
| 154 | if (weight > 0) { |
| 155 | substitutionMethods.add(new SubstituteBase(weight, parameters.getInt("negationOrder")) { |
| 156 | public void substitute(final int i) throws ProofException { |
| 157 | substituteNegation(i); |
| 158 | } |
| 159 | }); |
| 160 | } |
| 161 | weight = parameters.getInt("conjunctionWeight"); |
| 162 | if (weight > 0) { |
| 163 | substitutionMethods.add(new SubstituteBase(weight, parameters.getInt("conjunctionOrder")) { |
| 164 | public void substitute(final int i) throws ProofException { |
| 165 | substituteConjunction(i); |
| 166 | } |
| 167 | }); |
| 168 | } |
| 169 | weight = parameters.getInt("equivalenceWeight"); |
| 170 | if (weight > 0) { |
| 171 | substitutionMethods.add(new SubstituteBase(weight, parameters.getInt("equivalenceOrder")) { |
| 172 | public void substitute(final int i) throws ProofException { |
| 173 | substituteEquivalence(i); |
| 174 | } |
| 175 | }); |
| 176 | } |
| 177 | logFrequence = parameters.getInt("logFrequence"); |
| 178 | |
| 179 | lines = new ArrayList(); |
| 180 | reasons = new ArrayList(); |
| 181 | setAllPredVars(proof); |
| 182 | partGoalFormulas = FormulaUtility.getPartFormulas(goalFormula); |
| 183 | log.logMessageState("our goal: " + trans.getUtf8(formula)); |
| 184 | int size2 = 0; |
| 185 | while (true) { |
| 186 | // check if the thread should be interrupted |
| 187 | if (Thread.interrupted()) { |
| 188 | throw new InterruptException(this.context); |
| 189 | } |
| 190 | int size1 = lines.size(); |
| 191 | tryModusPonensAll(); |
| 192 | final Iterator iter = substitutionMethods.iterator(); |
| 193 | while (iter.hasNext()) { |
| 194 | final Substitute method = (Substitute) iter.next(); |
| 195 | // System.out.println(method.getClass()); |
| 196 | for (int j = 0; j < method.getWeight(); j++) { |
| 197 | if (method.nextLine() >= lines.size()) { |
| 198 | break; |
| 199 | } |
| 200 | method.substitute(); |
| 201 | tryModusPonensAll(); |
| 202 | } |
| 203 | } |
| 204 | // System.out.println(lines.size()); |
| 205 | if (size2 == lines.size()) { |
| 206 | // we didn't generate new lines, so we just quit |
| 207 | log.logMessageState(FinderErrors.PROOF_NOT_FOUND_TEXT + size2); |
| 208 | throw new ProofNotFoundException(FinderErrors.PROOF_NOT_FOUND_CODE, |
| 209 | FinderErrors.PROOF_NOT_FOUND_TEXT + size2, context); |
| 210 | } |
| 211 | size2 = size1; |
| 212 | } |
| 213 | } |
| 214 | |
| 215 | private void setAllPredVars(final FormalProofLineList proof) { |
| 216 | log.logMessageState("using the following formulas:"); |
| 217 | allPredVars = new ElementSet(); |
| 218 | // add all "add" proof formulas to our proof line list |
| 219 | for (int i = 0; i < proof.size(); i++) { |
| 220 | // should we skip this formula |
| 221 | if (skipFormulas.indexOf("," + (i + 1) + ",") >= 0) { |
| 222 | continue; |
| 223 | } |
| 224 | final Reason reason = proof.get(i).getReason(); |
| 225 | if (!(reason instanceof Add)) { |
| 226 | continue; |
| 227 | } |
| 228 | final Element formula = proof.get(i).getFormula().getElement(); |
| 229 | lines.add(formula); |
| 230 | reasons.add(reason); |
| 231 | log.logMessageState(ProofFinderUtility.getUtf8Line(formula, reason, i, trans)); |
| 232 | allPredVars.union(FormulaUtility.getPropositionVariables( |
| 233 | formula)); |
| 234 | } |
| 235 | String max = "A"; |
| 236 | final Iterator iter = allPredVars.iterator(); |
| 237 | while (iter.hasNext()) { |
| 238 | final ElementList v = (ElementList) iter.next(); |
| 239 | final String name = v.getElement(0).getAtom().getString(); |
| 240 | if (-1 == max.compareTo(name)) { |
| 241 | max = name; |
| 242 | } |
| 243 | } |
| 244 | System.out.println("Adding extra variables:"); |
| 245 | for (int i = 1; i <= extraVars; i++) { |
| 246 | max = (char) (max.charAt(0) + i) + ""; |
| 247 | System.out.println("\t" + max); |
| 248 | // add extra predicate variable |
| 249 | allPredVars.add(FormulaUtility.createPredicateVariable(max)); |
| 250 | } |
| 251 | } |
| 252 | |
| 253 | /** |
| 254 | * Try all Modus Ponens with all new lines. Remember tested maximum. |
| 255 | * |
| 256 | * @throws ProofException Proof found, or limits exceeded. |
| 257 | */ |
| 258 | private void tryModusPonensAll() throws ProofException { |
| 259 | int until = lines.size(); |
| 260 | for (int i = 0; i < until; i++) { |
| 261 | final Element first = (Element) lines.get(i); |
| 262 | if (!FormulaUtility.isImplication(first)) { |
| 263 | continue; |
| 264 | } |
| 265 | for (int j = (i < mpLast ? mpLast : 0); j < until; j++) { |
| 266 | if (first.getList().getElement(0).equals( |
| 267 | lines.get(j))) { |
| 268 | final ModusPonens mp = new ModusPonensBo(i, j); |
| 269 | addFormula(first.getList().getElement(1), mp); |
| 270 | } |
| 271 | } |
| 272 | } |
| 273 | mpLast = until; |
| 274 | } |
| 275 | |
| 276 | /** |
| 277 | * Make all possible substitutions by propositional variables in a proof line. |
| 278 | * |
| 279 | * @param i Proof line number we want to try substitution. |
| 280 | * @throws ProofException We found a proof or have to end the search! |
| 281 | */ |
| 282 | private void substituteByPropositionVariables(final int i) throws ProofException { |
| 283 | final Element f = (Element) lines.get(i); |
| 284 | final ElementSet vars = FormulaUtility.getPropositionVariables(f); |
| 285 | final Iterator iter = vars.iterator(); |
| 286 | while (iter.hasNext()) { |
| 287 | final ElementList var = (ElementList) iter.next(); |
| 288 | final Iterator all = allPredVars.iterator(); |
| 289 | while (all.hasNext()) { |
| 290 | final ElementList subst = (ElementList) all.next(); |
| 291 | if (var.equals(subst)) { |
| 292 | continue; |
| 293 | } |
| 294 | final Element created = FormulaUtility.replaceOperatorVariable( |
| 295 | f, var, subst); |
| 296 | addFormula(created, new SubstPredBo(i, var, subst)); |
| 297 | } |
| 298 | } |
| 299 | } |
| 300 | |
| 301 | /** |
| 302 | * Make all substitutions by part goal formulas in a proof line. |
| 303 | * |
| 304 | * @param i Proof line number we want to try substitution. |
| 305 | * @throws ProofException We found a proof or have to end the search! |
| 306 | */ |
| 307 | private void substitutePartGoalFormulas(final int i) throws ProofException { |
| 308 | final Element f = (Element) lines.get(i); |
| 309 | final ElementSet vars = FormulaUtility.getPropositionVariables(f); |
| 310 | final Iterator iter = vars.iterator(); |
| 311 | while (iter.hasNext()) { |
| 312 | final ElementList var = (ElementList) iter.next(); |
| 313 | { |
| 314 | final Iterator all = partGoalFormulas.iterator(); |
| 315 | while (all.hasNext()) { |
| 316 | final ElementList subst = (ElementList) all.next(); |
| 317 | if (var.equals(subst)) { |
| 318 | continue; |
| 319 | } |
| 320 | final Element created = FormulaUtility.replaceOperatorVariable( |
| 321 | f, var, subst); |
| 322 | addFormula(created, new SubstPredBo(i, var, subst)); |
| 323 | } |
| 324 | } |
| 325 | } |
| 326 | } |
| 327 | |
| 328 | /** |
| 329 | * Make all substitutions by negation in a proof line. |
| 330 | * |
| 331 | * @param i Proof line number we want to try substitution. |
| 332 | * @throws ProofException We found a proof or have to end the search! |
| 333 | */ |
| 334 | private void substituteNegation(final int i) throws ProofException { |
| 335 | final Element f = (Element) lines.get(i); |
| 336 | final ElementSet vars = FormulaUtility.getPropositionVariables(f); |
| 337 | final Iterator iter = vars.iterator(); |
| 338 | while (iter.hasNext()) { |
| 339 | final ElementList var = (ElementList) iter.next(); |
| 340 | final Iterator all = allPredVars.iterator(); |
| 341 | while (all.hasNext()) { |
| 342 | final ElementList var2 = (ElementList) all.next(); |
| 343 | final ElementList subst = new DefaultElementList(Operators.NEGATION_OPERATOR); |
| 344 | subst.add(var2); |
| 345 | final Element created = FormulaUtility.replaceOperatorVariable( |
| 346 | f, var, subst); |
| 347 | addFormula(created, new SubstPredBo(i, var, subst)); |
| 348 | } |
| 349 | } |
| 350 | } |
| 351 | |
| 352 | /** |
| 353 | * Make all substitutions by conjunction in a proof line. |
| 354 | * |
| 355 | * @param i Proof line number we want to try substitution. |
| 356 | * @throws ProofException We found a proof or have to end the search! |
| 357 | */ |
| 358 | private void substituteConjunction(final int i) throws ProofException { |
| 359 | final Element f = (Element) lines.get(i); |
| 360 | final ElementSet vars = FormulaUtility.getPropositionVariables(f); |
| 361 | final Iterator iter = vars.iterator(); |
| 362 | while (iter.hasNext()) { |
| 363 | final ElementList var = (ElementList) iter.next(); |
| 364 | createReplacement(i, f, var, Operators.CONJUNCTION_OPERATOR, true); |
| 365 | createReplacement(i, f, var, Operators.CONJUNCTION_OPERATOR, false); |
| 366 | } |
| 367 | } |
| 368 | |
| 369 | /** |
| 370 | * Make all substitutions by disjunction in a proof line. |
| 371 | * |
| 372 | * @param i Proof line number we want to try substitution. |
| 373 | * @throws ProofException We found a proof or have to end the search! |
| 374 | */ |
| 375 | private void substituteDisjunction(final int i) throws ProofException { |
| 376 | final Element f = (Element) lines.get(i); |
| 377 | final ElementSet vars = FormulaUtility.getPropositionVariables(f); |
| 378 | final Iterator iter = vars.iterator(); |
| 379 | while (iter.hasNext()) { |
| 380 | final ElementList var = (ElementList) iter.next(); |
| 381 | createReplacement(i, f, var, Operators.DISJUNCTION_OPERATOR, true); |
| 382 | createReplacement(i, f, var, Operators.DISJUNCTION_OPERATOR, false); |
| 383 | } |
| 384 | } |
| 385 | |
| 386 | /** |
| 387 | * Make all substitutions by implication in a proof line. |
| 388 | * |
| 389 | * @param i Proof line number we want to try substitution. |
| 390 | * @throws ProofException We found a proof or have to end the search! |
| 391 | */ |
| 392 | private void substituteImplication(final int i) throws ProofException { |
| 393 | final Element f = (Element) lines.get(i); |
| 394 | final ElementSet vars = FormulaUtility.getPropositionVariables(f); |
| 395 | final Iterator iter = vars.iterator(); |
| 396 | while (iter.hasNext()) { |
| 397 | final ElementList var = (ElementList) iter.next(); |
| 398 | createReplacement(i, f, var, Operators.IMPLICATION_OPERATOR, true); |
| 399 | createReplacement(i, f, var, Operators.IMPLICATION_OPERATOR, false); |
| 400 | } |
| 401 | } |
| 402 | |
| 403 | /** |
| 404 | * Make all substitutions by equivalence in a proof line. |
| 405 | * |
| 406 | * @param i Proof line number we want to try substitution. |
| 407 | * @throws ProofException We found a proof or have to end the search! |
| 408 | */ |
| 409 | private void substituteEquivalence(final int i) throws ProofException { |
| 410 | final Element f = (Element) lines.get(i); |
| 411 | final ElementSet vars = FormulaUtility.getPropositionVariables(f); |
| 412 | final Iterator iter = vars.iterator(); |
| 413 | while (iter.hasNext()) { |
| 414 | final ElementList var = (ElementList) iter.next(); |
| 415 | createReplacement(i, f, var, Operators.EQUIVALENCE_OPERATOR, true); |
| 416 | createReplacement(i, f, var, Operators.EQUIVALENCE_OPERATOR, false); |
| 417 | } |
| 418 | } |
| 419 | |
| 420 | /** |
| 421 | * Substitute predicate variable <code>var</code> by binary operator with old variable |
| 422 | * and new variable and add this as a new proof line. |
| 423 | * |
| 424 | * @param i Proof line number we work on. |
| 425 | * @param f Proof line formula. |
| 426 | * @param var Predicate variable we want to replace. |
| 427 | * @param operator Operator of replacement formula. |
| 428 | * @param left Is old variable at left hand of new operator? |
| 429 | * @throws ProofException We found a proof or have to end the search! |
| 430 | */ |
| 431 | private void createReplacement(final int i, final Element f, |
| 432 | final ElementList var, final String operator, final boolean left) throws ProofException { |
| 433 | final Iterator a = allPredVars.iterator(); |
| 434 | while (a.hasNext()) { |
| 435 | final ElementList var2 = (ElementList) a.next(); |
| 436 | final ElementList subst = new DefaultElementList(operator); |
| 437 | if (left) { |
| 438 | subst.add(var); |
| 439 | subst.add(var2); |
| 440 | } else { |
| 441 | subst.add(var2); |
| 442 | subst.add(var); |
| 443 | } |
| 444 | final Element created = FormulaUtility.replaceOperatorVariable( |
| 445 | f, var, subst); |
| 446 | addFormula(created, new SubstPredBo(i, var, subst)); |
| 447 | } |
| 448 | } |
| 449 | |
| 450 | private void addFormula(final Element formula, final Reason reason) throws ProofException { |
| 451 | if (!lines.contains(formula)) { |
| 452 | lines.add(formula); |
| 453 | reasons.add(reason); |
| 454 | // printLine(lines.size() - 1); |
| 455 | if (goalFormula.equals(formula)) { |
| 456 | final int size = lines.size(); |
| 457 | log.logMessageState(FinderErrors.PROOF_FOUND_TEXT + size); |
| 458 | throw new ProofFoundException(FinderErrors.PROOF_FOUND_CODE, |
| 459 | FinderErrors.PROOF_FOUND_TEXT + size, |
| 460 | ProofFinderUtility.shortenProof(lines, reasons, log, trans), context); |
| 461 | } |
| 462 | // did we reach our maximum? |
| 463 | if (lines.size() >= maxProofLines) { |
| 464 | final int size = lines.size(); |
| 465 | if (logFrequence > 0) { |
| 466 | log.logMessageState(ProofFinderUtility.getUtf8Line(lines, reasons, lines.size() - 1, |
| 467 | trans)); |
| 468 | } |
| 469 | log.logMessageState(FinderErrors.PROOF_NOT_FOUND_TEXT + size); |
| 470 | throw new ProofNotFoundException(FinderErrors.PROOF_NOT_FOUND_CODE, |
| 471 | FinderErrors.PROOF_NOT_FOUND_TEXT + size, context); |
| 472 | } |
| 473 | if (logFrequence > 0 && (lines.size() - 1) % logFrequence == 0) { |
| 474 | log.logMessageState(ProofFinderUtility.getUtf8Line(lines, reasons, lines.size() - 1, |
| 475 | trans)); |
| 476 | } |
| 477 | } |
| 478 | } |
| 479 | |
| 480 | public String getExecutionActionDescription() { |
| 481 | return ProofFinderUtility.getUtf8Line(lines, reasons, lines.size() - 1, trans); |
| 482 | } |
| 483 | |
| 484 | /** |
| 485 | * These is the basis implementation for substitution methods. |
| 486 | */ |
| 487 | private abstract class SubstituteBase implements Substitute { |
| 488 | |
| 489 | /** Next proof line we will work on. */ |
| 490 | private int next = 0; |
| 491 | |
| 492 | /** Weight of proof method. */ |
| 493 | private final int weight; |
| 494 | |
| 495 | /** Order of proof method. */ |
| 496 | private final int order; |
| 497 | |
| 498 | SubstituteBase(final int weight, final int order) { |
| 499 | this.weight = weight; |
| 500 | this.order = order; |
| 501 | } |
| 502 | |
| 503 | public int getWeight() { |
| 504 | return weight; |
| 505 | } |
| 506 | |
| 507 | public int getOrder() { |
| 508 | return order; |
| 509 | } |
| 510 | public int nextLine() { |
| 511 | return next; |
| 512 | } |
| 513 | |
| 514 | public int compareTo(final Object obj) { |
| 515 | if (obj instanceof Substitute) { |
| 516 | Substitute sub = (Substitute) obj; |
| 517 | // we don't return 0 because the TreeSet gets no more elements |
| 518 | // if we have methods with same order value |
| 519 | if (order == sub.getOrder()) { |
| 520 | return -1; |
| 521 | } |
| 522 | if (order < sub.getOrder()) { |
| 523 | return -1; |
| 524 | } |
| 525 | return 1; |
| 526 | } |
| 527 | return -1; |
| 528 | } |
| 529 | |
| 530 | public void substitute() throws ProofException { |
| 531 | substitute(next); |
| 532 | next++; |
| 533 | } |
| 534 | |
| 535 | public abstract void substitute(int i) throws ProofException; |
| 536 | |
| 537 | } |
| 538 | |
| 539 | |
| 540 | /** |
| 541 | * Work on proof line and substitute proposition variables. |
| 542 | * |
| 543 | */ |
| 544 | interface Substitute extends Comparable { |
| 545 | |
| 546 | /** |
| 547 | * Return next proof line number we will work on. |
| 548 | * |
| 549 | * @return Next proof line number we will worked on. |
| 550 | */ |
| 551 | public int nextLine(); |
| 552 | |
| 553 | /** |
| 554 | * Substitute next proof line number. |
| 555 | * |
| 556 | * @throws ProofException We found a proof or have to end the search! |
| 557 | */ |
| 558 | public void substitute() throws ProofException; |
| 559 | |
| 560 | /** |
| 561 | * Get weight of substitution rule. This is the number of runs for this |
| 562 | * substitution. |
| 563 | * |
| 564 | * @return Weight. |
| 565 | */ |
| 566 | public int getWeight(); |
| 567 | |
| 568 | /** |
| 569 | * Get order position of substitution rule. This says about the sequence position of this |
| 570 | * substitution method. |
| 571 | * |
| 572 | * @return Order position. |
| 573 | */ |
| 574 | public int getOrder(); |
| 575 | |
| 576 | } |
| 577 | |
| 578 | } |