diff --git a/src/Composer/DependencyResolver/Pool.php b/src/Composer/DependencyResolver/Pool.php
index 7088b3d50..0ab1b67e4 100644
--- a/src/Composer/DependencyResolver/Pool.php
+++ b/src/Composer/DependencyResolver/Pool.php
@@ -87,20 +87,20 @@ class Pool implements \Countable
      *                                            packages must match or null to return all
      * @return PackageInterface[]  A set of packages
      */
-    public function whatProvides($name, ConstraintInterface $constraint = null, $allowProvide = true)
+    public function whatProvides($name, ConstraintInterface $constraint = null)
     {
-        $key = ((int) $allowProvide).$constraint;
+        $key = (string) $constraint;
         if (isset($this->providerCache[$name][$key])) {
             return $this->providerCache[$name][$key];
         }
 
-        return $this->providerCache[$name][$key] = $this->computeWhatProvides($name, $constraint, $allowProvide);
+        return $this->providerCache[$name][$key] = $this->computeWhatProvides($name, $constraint);
     }
 
     /**
      * @see whatProvides
      */
-    private function computeWhatProvides($name, $constraint, $allowProvide = true)
+    private function computeWhatProvides($name, $constraint)
     {
         if (!isset($this->packageByName[$name])) {
             return array();
@@ -113,14 +113,9 @@ class Pool implements \Countable
                 case self::MATCH_NONE:
                     break;
 
-                case self::MATCH_PROVIDE:
-                    if ($allowProvide) {
-                        $matches[] = $candidate;
-                    }
-                    break;
-
                 case self::MATCH:
                 case self::MATCH_REPLACE:
+                case self::MATCH_PROVIDE:
                     $matches[] = $candidate;
                     break;
 
diff --git a/src/Composer/DependencyResolver/Rule.php b/src/Composer/DependencyResolver/Rule.php
index fe1afd12e..7885efda3 100644
--- a/src/Composer/DependencyResolver/Rule.php
+++ b/src/Composer/DependencyResolver/Rule.php
@@ -29,10 +29,7 @@ abstract class Rule
     const RULE_FIXED = 3;
     const RULE_PACKAGE_CONFLICT = 6;
     const RULE_PACKAGE_REQUIRES = 7;
-    const RULE_PACKAGE_OBSOLETES = 8;
-    const RULE_INSTALLED_PACKAGE_OBSOLETES = 9;
     const RULE_PACKAGE_SAME_NAME = 10;
-    const RULE_PACKAGE_IMPLICIT_OBSOLETES = 11;
     const RULE_LEARNED = 12;
     const RULE_PACKAGE_ALIAS = 13;
 
@@ -191,83 +188,50 @@ abstract class Rule
 
                 return $text;
 
-            case self::RULE_PACKAGE_OBSOLETES:
-                if (count($literals) === 2 && $literals[0] < 0 && $literals[1] < 0) {
-                    $package1 = $pool->literalToPackage($literals[0]);
-                    $package2 = $pool->literalToPackage($literals[1]);
-
-                    $replaces1 = $this->getReplacedNames($package1);
-                    $replaces2 = $this->getReplacedNames($package2);
-
-                    $reason = null;
-                    if ($conflictingNames = array_values(array_intersect($replaces1, $replaces2))) {
-                        $reason = 'They both replace '.(count($conflictingNames) > 1 ? '['.implode(', ', $conflictingNames).']' : $conflictingNames[0]).' and thus cannot coexist.';
-                    } elseif (in_array($package1->getName(), $replaces2, true)) {
-                        $reason = $package2->getName().' replaces '.$package1->getName().' and thus cannot coexist with it.';
-                    } elseif (in_array($package2->getName(), $replaces1, true)) {
-                        $reason = $package1->getName().' replaces '.$package2->getName().' and thus cannot coexist with it.';
-                    }
-
-                    if ($reason) {
-                        if (isset($installedMap[$package1->id]) && !isset($installedMap[$package2->id])) {
-                            // swap vars so the if below passes
-                            $tmp = $package2;
-                            $package2 = $package1;
-                            $package1 = $tmp;
-                        }
-                        if (!isset($installedMap[$package1->id]) && isset($installedMap[$package2->id])) {
-                            return $package1->getPrettyString().' cannot be installed as that would require removing '.$package2->getPrettyString().'. '.$reason;
-                        }
-
-                        if (!isset($installedMap[$package1->id]) && !isset($installedMap[$package2->id])) {
-                            return 'Only one of these can be installed: '.$package1->getPrettyString().', '.$package2->getPrettyString().'. '.$reason;
-                        }
-                    }
-
-                    return 'Only one of these can be installed: '.$package1->getPrettyString().', '.$package2->getPrettyString().'.';
-                }
-
-                return $ruleText;
-            case self::RULE_INSTALLED_PACKAGE_OBSOLETES:
-                return $ruleText;
             case self::RULE_PACKAGE_SAME_NAME:
-                $replacedNames = null;
                 $packageNames = array();
                 foreach ($literals as $literal) {
                     $package = $pool->literalToPackage($literal);
-                    $pkgReplaces = $this->getReplacedNames($package);
-                    if ($pkgReplaces) {
-                        if ($replacedNames === null) {
-                            $replacedNames = $this->getReplacedNames($package);
+                    $packageNames[$package->getName()] = true;
+                }
+                $replacedName = $this->reasonData;
+
+                if (count($packageNames) > 1) {
+                    $reason = null;
+
+                    if (!isset($packageNames[$replacedName])) {
+                        $reason = 'They '.(count($literals) == 2 ? 'both' : 'all').' replace '.$replacedName.' and thus cannot coexist.';
+                    } else {
+                        $replacerNames = $packageNames;
+                        unset($replacerNames[$replacedName]);
+                        $replacerNames = array_keys($replacerNames);
+
+                        if (count($replacerNames) == 1) {
+                            $reason = $replacerNames[0] . ' replaces ';
                         } else {
-                            $replacedNames = array_intersect($replacedNames, $this->getReplacedNames($package));
+                            $reason = '['.implode(', ', $replacerNames).'] replace ';
                         }
+                        $reason .= $replacedName.' and thus cannot coexist with it.';
                     }
-                    $packageNames[$package->getName()] = true;
-                }
 
-                if ($replacedNames) {
-                    $replacedNames = array_values(array_intersect(array_keys($packageNames), $replacedNames));
-                }
-                if ($replacedNames && count($packageNames) > 1) {
-                    $replacer = null;
+                    $installedPackages = array();
+                    $removablePackages = array();
                     foreach ($literals as $literal) {
-                        $package = $pool->literalToPackage($literal);
-                        if (array_intersect($replacedNames, $this->getReplacedNames($package))) {
-                            $replacer = $package;
-                            break;
+                        if (isset($installedMap[abs($literal)])) {
+                            $installedPackages[] = $pool->literalToPackage($literal);
+                        } else {
+                            $removablePackages[] = $pool->literalToPackage($literal);
                         }
                     }
-                    $replacedNames = count($replacedNames) > 1 ? '['.implode(', ', $replacedNames).']' : $replacedNames[0];
 
-                    if ($replacer) {
-                        return 'Only one of these can be installed: ' . $this->formatPackagesUnique($pool, $literals) . '. '.$replacer->getName().' replaces '.$replacedNames.' and thus cannot coexist with it.';
+                    if ($installedPackages && $removablePackages) {
+                        return $this->formatPackagesUnique($pool, $removablePackages).' cannot be installed as that would require removing '.$this->formatPackagesUnique($pool, $installedPackages).'. '.$reason;
                     }
+
+                    return 'Only one of these can be installed: '.$this->formatPackagesUnique($pool, $literals).'. '.$reason;
                 }
 
                 return 'You can only install one version of a package, so only one of these can be installed: ' . $this->formatPackagesUnique($pool, $literals) . '.';
-            case self::RULE_PACKAGE_IMPLICIT_OBSOLETES:
-                return $ruleText;
             case self::RULE_LEARNED:
                 if (isset($learnedPool[$this->reasonData])) {
                     $learnedString = ', learned rules:'."\n        - ";
diff --git a/src/Composer/DependencyResolver/RuleSetGenerator.php b/src/Composer/DependencyResolver/RuleSetGenerator.php
index ca10702a2..e6ac7ac31 100644
--- a/src/Composer/DependencyResolver/RuleSetGenerator.php
+++ b/src/Composer/DependencyResolver/RuleSetGenerator.php
@@ -160,8 +160,12 @@ class RuleSetGenerator
             $this->addedMap[$package->id] = true;
 
             $this->addedPackages[] = $package;
-            foreach ($package->getNames(false) as $name) {
-                $this->addedPackagesByNames[$name][] = $package;
+            if (!$package instanceof AliasPackage) {
+                foreach ($package->getNames(false) as $name) {
+                    $this->addedPackagesByNames[$name][] = $package;
+                }
+            } else {
+                $this->addRule(RuleSet::TYPE_PACKAGE, $this->createRequireRule($package, array($package->getAliasOf()), Rule::RULE_PACKAGE_ALIAS, $package));
             }
 
             foreach ($package->getRequires() as $link) {
@@ -177,29 +181,6 @@ class RuleSetGenerator
                     $workQueue->enqueue($require);
                 }
             }
-
-            $packageName = $package->getName();
-            $obsoleteProviders = $this->pool->whatProvides($packageName, null, false);
-
-            foreach ($obsoleteProviders as $provider) {
-                if ($provider === $package) {
-                    continue;
-                }
-
-                if (($package instanceof AliasPackage) && $package->getAliasOf() === $provider) {
-                    $this->addRule(RuleSet::TYPE_PACKAGE, $this->createRequireRule($package, array($provider), Rule::RULE_PACKAGE_ALIAS, $package));
-                } else {
-                    if (!isset($this->conflictsForName[$packageName])) {
-                        $this->conflictsForName[$packageName] = array();
-                    }
-                    if (!$package instanceof AliasPackage) {
-                        $this->conflictsForName[$packageName][$package->id] = $package;
-                    }
-                    if (!$provider instanceof AliasPackage) {
-                        $this->conflictsForName[$packageName][$provider->id] = $provider;
-                    }
-                }
-            }
         }
     }
 
@@ -218,39 +199,17 @@ class RuleSetGenerator
 
                 /** @var PackageInterface $possibleConflict */
                 foreach ($this->addedPackagesByNames[$link->getTarget()] as $possibleConflict) {
-                    $conflictMatch = $this->pool->match($possibleConflict, $link->getTarget(), $link->getConstraint());
-
-                    if ($conflictMatch === Pool::MATCH || $conflictMatch === Pool::MATCH_REPLACE) {
+                    if ($this->pool->match($possibleConflict, $link->getTarget(), $link->getConstraint())) {
                         $this->addRule(RuleSet::TYPE_PACKAGE, $this->createRule2Literals($package, $possibleConflict, Rule::RULE_PACKAGE_CONFLICT, $link));
                     }
-
-                }
-            }
-
-            // check obsoletes and implicit obsoletes of a package
-            foreach ($package->getReplaces() as $link) {
-                if (!isset($this->addedPackagesByNames[$link->getTarget()])) {
-                    continue;
-                }
-
-                /** @var PackageInterface $possibleConflict */
-                foreach ($this->addedPackagesByNames[$link->getTarget()] as $provider) {
-                    if ($provider === $package) {
-                        continue;
-                    }
-
-                    if (!$this->obsoleteImpossibleForAlias($package, $provider)) {
-                        $reason = Rule::RULE_PACKAGE_OBSOLETES;
-                        $this->addRule(RuleSet::TYPE_PACKAGE, $this->createRule2Literals($package, $provider, $reason, $link));
-                    }
                 }
             }
         }
 
-        foreach ($this->conflictsForName as $name => $packages) {
+        foreach ($this->addedPackagesByNames as $name => $packages) {
             if (count($packages) > 1) {
                 $reason = Rule::RULE_PACKAGE_SAME_NAME;
-                $this->addRule(RuleSet::TYPE_PACKAGE, $this->createMultiConflictRule($packages, $reason, null));
+                $this->addRule(RuleSet::TYPE_PACKAGE, $this->createMultiConflictRule($packages, $reason, $name));
             }
         }
     }
diff --git a/tests/Composer/Test/Fixtures/installer/provider-conflicts.test b/tests/Composer/Test/Fixtures/installer/provider-conflicts.test
index 3a9700103..a73dd3dc9 100644
--- a/tests/Composer/Test/Fixtures/installer/provider-conflicts.test
+++ b/tests/Composer/Test/Fixtures/installer/provider-conflicts.test
@@ -42,7 +42,7 @@ Your requirements could not be resolved to an installable set of packages.
 
   Problem 1
     - __root__ is present at version 1.2.3 and cannot be modified by Composer
-    - provider/pkg 1.0.0 cannot be installed as that would require removing __root__ 1.2.3. They both replace root-replaced/transitive-replaced and thus cannot coexist.
+    - provider/pkg[1.0.0] cannot be installed as that would require removing __root__[1.2.3]. They both replace root-replaced/transitive-replaced and thus cannot coexist.
     - Root composer.json requires provider/pkg * -> satisfiable by provider/pkg[1.0.0].
 
 --EXPECT--