diff --git a/.vscode/settings.json b/.vscode/settings.json
index 6af9e8b..b7ad7ef 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -8,10 +8,8 @@
     // php-cs-fixer settings
     "php-cs-fixer.config": ".php-cs-fixer.dist.php",
     "php-cs-fixer.executablePath": "${workspaceFolder}/vendor/friendsofphp/php-cs-fixer/php-cs-fixer",
-    // HACK: PHP8.4 に PHP-CS-Fixer が対応していないが強制的に実行するための設定
-    // TODO: PHP-CS-Fixer が PHP8.4 に対応したら削除すること！！！！
-    "php-cs-fixer.ignorePHPVersion": true,
     // PHPStan settings
+    "phpstan.enabled": true,
     "phpstan.binPath": "vendor/bin/phpstan",
     "phpstan.configFile": "phpstan.neon.dist",
     "phpstan.singleFileMode": true,
diff --git a/composer.json b/composer.json
index 34f8d4d..7889636 100644
--- a/composer.json
+++ b/composer.json
@@ -32,8 +32,7 @@
         "phpunit/php-code-coverage": "^11.0",
         "phpunit/phpunit": "^11.3",
         "phpstan/extension-installer": "^1.4",
-        "phpstan/phpstan-strict-rules": "^1.6",
-        "wiz-develop/php-value-object": "^0.5"
+        "phpstan/phpstan-strict-rules": "^1.6"
     },
     "config": {
         "allow-plugins": {
diff --git a/composer.lock b/composer.lock
index cea7a7f..5fa89b6 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "a9500cf9a60bafecd4f49e8284bea141",
+    "content-hash": "8dd7a8c2a59983f4d1f966ceb808189e",
     "packages": [],
     "packages-dev": [
         {
@@ -407,20 +407,20 @@
         },
         {
             "name": "friendsofphp/php-cs-fixer",
-            "version": "v3.84.0",
+            "version": "v3.85.1",
             "source": {
                 "type": "git",
                 "url": "https://github.com/PHP-CS-Fixer/PHP-CS-Fixer.git",
-                "reference": "38dad0767bf2a9b516b976852200ae722fe984ca"
+                "reference": "2fb6d7f6c3398dca5786a1635b27405d73a417ba"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/PHP-CS-Fixer/PHP-CS-Fixer/zipball/38dad0767bf2a9b516b976852200ae722fe984ca",
-                "reference": "38dad0767bf2a9b516b976852200ae722fe984ca",
+                "url": "https://api.github.com/repos/PHP-CS-Fixer/PHP-CS-Fixer/zipball/2fb6d7f6c3398dca5786a1635b27405d73a417ba",
+                "reference": "2fb6d7f6c3398dca5786a1635b27405d73a417ba",
                 "shasum": ""
             },
             "require": {
-                "clue/ndjson-react": "^1.0",
+                "clue/ndjson-react": "^1.3",
                 "composer/semver": "^3.4",
                 "composer/xdebug-handler": "^3.0.5",
                 "ext-filter": "*",
@@ -430,12 +430,12 @@
                 "fidry/cpu-core-counter": "^1.2",
                 "php": "^7.4 || ^8.0",
                 "react/child-process": "^0.6.6",
-                "react/event-loop": "^1.0",
-                "react/promise": "^2.11 || ^3.0",
-                "react/socket": "^1.0",
-                "react/stream": "^1.0",
+                "react/event-loop": "^1.5",
+                "react/promise": "^3.2",
+                "react/socket": "^1.16",
+                "react/stream": "^1.4",
                 "sebastian/diff": "^4.0.6 || ^5.1.1 || ^6.0.2 || ^7.0",
-                "symfony/console": "^5.4.45 || ^6.4.13 || ^7.0",
+                "symfony/console": "^5.4.47 || ^6.4.13 || ^7.0",
                 "symfony/event-dispatcher": "^5.4.45 || ^6.4.13 || ^7.0",
                 "symfony/filesystem": "^5.4.45 || ^6.4.13 || ^7.0",
                 "symfony/finder": "^5.4.45 || ^6.4.17 || ^7.0",
@@ -500,7 +500,7 @@
             ],
             "support": {
                 "issues": "https://github.com/PHP-CS-Fixer/PHP-CS-Fixer/issues",
-                "source": "https://github.com/PHP-CS-Fixer/PHP-CS-Fixer/tree/v3.84.0"
+                "source": "https://github.com/PHP-CS-Fixer/PHP-CS-Fixer/tree/v3.85.1"
             },
             "funding": [
                 {
@@ -508,20 +508,20 @@
                     "type": "github"
                 }
             ],
-            "time": "2025-07-15T18:21:57+00:00"
+            "time": "2025-07-29T22:22:50+00:00"
         },
         {
             "name": "myclabs/deep-copy",
-            "version": "1.13.3",
+            "version": "1.13.4",
             "source": {
                 "type": "git",
                 "url": "https://github.com/myclabs/DeepCopy.git",
-                "reference": "faed855a7b5f4d4637717c2b3863e277116beb36"
+                "reference": "07d290f0c47959fd5eed98c95ee5602db07e0b6a"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/myclabs/DeepCopy/zipball/faed855a7b5f4d4637717c2b3863e277116beb36",
-                "reference": "faed855a7b5f4d4637717c2b3863e277116beb36",
+                "url": "https://api.github.com/repos/myclabs/DeepCopy/zipball/07d290f0c47959fd5eed98c95ee5602db07e0b6a",
+                "reference": "07d290f0c47959fd5eed98c95ee5602db07e0b6a",
                 "shasum": ""
             },
             "require": {
@@ -560,7 +560,7 @@
             ],
             "support": {
                 "issues": "https://github.com/myclabs/DeepCopy/issues",
-                "source": "https://github.com/myclabs/DeepCopy/tree/1.13.3"
+                "source": "https://github.com/myclabs/DeepCopy/tree/1.13.4"
             },
             "funding": [
                 {
@@ -568,20 +568,20 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2025-07-05T12:25:42+00:00"
+            "time": "2025-08-01T08:46:24+00:00"
         },
         {
             "name": "nikic/php-parser",
-            "version": "v5.5.0",
+            "version": "v5.6.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/nikic/PHP-Parser.git",
-                "reference": "ae59794362fe85e051a58ad36b289443f57be7a9"
+                "reference": "221b0d0fdf1369c71047ad1d18bb5880017bbc56"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/nikic/PHP-Parser/zipball/ae59794362fe85e051a58ad36b289443f57be7a9",
-                "reference": "ae59794362fe85e051a58ad36b289443f57be7a9",
+                "url": "https://api.github.com/repos/nikic/PHP-Parser/zipball/221b0d0fdf1369c71047ad1d18bb5880017bbc56",
+                "reference": "221b0d0fdf1369c71047ad1d18bb5880017bbc56",
                 "shasum": ""
             },
             "require": {
@@ -624,9 +624,9 @@
             ],
             "support": {
                 "issues": "https://github.com/nikic/PHP-Parser/issues",
-                "source": "https://github.com/nikic/PHP-Parser/tree/v5.5.0"
+                "source": "https://github.com/nikic/PHP-Parser/tree/v5.6.0"
             },
-            "time": "2025-05-31T08:24:38+00:00"
+            "time": "2025-07-27T20:03:57+00:00"
         },
         {
             "name": "phar-io/manifest",
@@ -796,16 +796,16 @@
         },
         {
             "name": "phpstan/phpstan",
-            "version": "1.12.27",
+            "version": "1.12.28",
             "source": {
                 "type": "git",
                 "url": "https://github.com/phpstan/phpstan.git",
-                "reference": "3a6e423c076ab39dfedc307e2ac627ef579db162"
+                "reference": "fcf8b71aeab4e1a1131d1783cef97b23a51b87a9"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/3a6e423c076ab39dfedc307e2ac627ef579db162",
-                "reference": "3a6e423c076ab39dfedc307e2ac627ef579db162",
+                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/fcf8b71aeab4e1a1131d1783cef97b23a51b87a9",
+                "reference": "fcf8b71aeab4e1a1131d1783cef97b23a51b87a9",
                 "shasum": ""
             },
             "require": {
@@ -850,7 +850,7 @@
                     "type": "github"
                 }
             ],
-            "time": "2025-05-21T20:51:45+00:00"
+            "time": "2025-07-17T17:15:39+00:00"
         },
         {
             "name": "phpstan/phpstan-strict-rules",
@@ -1238,16 +1238,16 @@
         },
         {
             "name": "phpunit/phpunit",
-            "version": "11.5.27",
+            "version": "11.5.32",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sebastianbergmann/phpunit.git",
-                "reference": "446d43867314781df7e9adf79c3ec7464956fd8f"
+                "reference": "101e132dcf9e74a1eb3a309b4f686114ae8f7f36"
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                 "type": "zip",
-                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/446d43867314781df7e9adf79c3ec7464956fd8f",
-                "reference": "446d43867314781df7e9adf79c3ec7464956fd8f",
+                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/101e132dcf9e74a1eb3a309b4f686114ae8f7f36",
+                "reference": "101e132dcf9e74a1eb3a309b4f686114ae8f7f36",
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@@ -1257,7 +1257,7 @@
                 "ext-mbstring": "*",
                 "ext-xml": "*",
                 "ext-xmlwriter": "*",
-                "myclabs/deep-copy": "^1.13.3",
+                "myclabs/deep-copy": "^1.13.4",
                 "phar-io/manifest": "^2.0.4",
                 "phar-io/version": "^3.2.1",
                 "php": ">=8.2",
@@ -1268,13 +1268,13 @@
                 "phpunit/php-timer": "^7.0.1",
                 "sebastian/cli-parser": "^3.0.2",
                 "sebastian/code-unit": "^3.0.3",
-                "sebastian/comparator": "^6.3.1",
+                "sebastian/comparator": "^6.3.2",
                 "sebastian/diff": "^6.0.2",
                 "sebastian/environment": "^7.2.1",
                 "sebastian/exporter": "^6.3.0",
                 "sebastian/global-state": "^7.0.2",
                 "sebastian/object-enumerator": "^6.0.1",
-                "sebastian/type": "^5.1.2",
+                "sebastian/type": "^5.1.3",
                 "sebastian/version": "^5.0.2",
                 "staabm/side-effects-detector": "^1.0.5"
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@@ -1319,7 +1319,7 @@
             "support": {
                 "issues": "https://github.com/sebastianbergmann/phpunit/issues",
                 "security": "https://github.com/sebastianbergmann/phpunit/security/policy",
-                "source": "https://github.com/sebastianbergmann/phpunit/tree/11.5.27"
+                "source": "https://github.com/sebastianbergmann/phpunit/tree/11.5.32"
             },
             "funding": [
                 {
@@ -1343,7 +1343,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2025-07-11T04:10:06+00:00"
+            "time": "2025-08-12T07:32:49+00:00"
         },
         {
             "name": "psr/container",
@@ -2196,16 +2196,16 @@
         },
         {
             "name": "sebastian/comparator",
-            "version": "6.3.1",
+            "version": "6.3.2",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sebastianbergmann/comparator.git",
-                "reference": "24b8fbc2c8e201bb1308e7b05148d6ab393b6959"
+                "reference": "85c77556683e6eee4323e4c5468641ca0237e2e8"
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-                "url": "https://api.github.com/repos/sebastianbergmann/comparator/zipball/24b8fbc2c8e201bb1308e7b05148d6ab393b6959",
-                "reference": "24b8fbc2c8e201bb1308e7b05148d6ab393b6959",
+                "url": "https://api.github.com/repos/sebastianbergmann/comparator/zipball/85c77556683e6eee4323e4c5468641ca0237e2e8",
+                "reference": "85c77556683e6eee4323e4c5468641ca0237e2e8",
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@@ -2264,15 +2264,27 @@
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                 "security": "https://github.com/sebastianbergmann/comparator/security/policy",
-                "source": "https://github.com/sebastianbergmann/comparator/tree/6.3.1"
+                "source": "https://github.com/sebastianbergmann/comparator/tree/6.3.2"
             },
             "funding": [
                 {
                     "url": "https://github.com/sebastianbergmann",
                     "type": "github"
+                },
+                {
+                    "url": "https://liberapay.com/sebastianbergmann",
+                    "type": "liberapay"
+                },
+                {
+                    "url": "https://thanks.dev/u/gh/sebastianbergmann",
+                    "type": "thanks_dev"
+                },
+                {
+                    "url": "https://tidelift.com/funding/github/packagist/sebastian/comparator",
+                    "type": "tidelift"
                 }
             ],
-            "time": "2025-03-07T06:57:01+00:00"
+            "time": "2025-08-10T08:07:46+00:00"
         },
         {
             "name": "sebastian/complexity",
@@ -2789,23 +2801,23 @@
         },
         {
             "name": "sebastian/recursion-context",
-            "version": "6.0.2",
+            "version": "6.0.3",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sebastianbergmann/recursion-context.git",
-                "reference": "694d156164372abbd149a4b85ccda2e4670c0e16"
+                "reference": "f6458abbf32a6c8174f8f26261475dc133b3d9dc"
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-                "url": "https://api.github.com/repos/sebastianbergmann/recursion-context/zipball/694d156164372abbd149a4b85ccda2e4670c0e16",
-                "reference": "694d156164372abbd149a4b85ccda2e4670c0e16",
+                "url": "https://api.github.com/repos/sebastianbergmann/recursion-context/zipball/f6458abbf32a6c8174f8f26261475dc133b3d9dc",
+                "reference": "f6458abbf32a6c8174f8f26261475dc133b3d9dc",
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             },
             "require": {
                 "php": ">=8.2"
             },
             "require-dev": {
-                "phpunit/phpunit": "^11.0"
+                "phpunit/phpunit": "^11.3"
             },
             "type": "library",
             "extra": {
@@ -2841,28 +2853,40 @@
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                 "security": "https://github.com/sebastianbergmann/recursion-context/security/policy",
-                "source": "https://github.com/sebastianbergmann/recursion-context/tree/6.0.2"
+                "source": "https://github.com/sebastianbergmann/recursion-context/tree/6.0.3"
             },
             "funding": [
                 {
                     "url": "https://github.com/sebastianbergmann",
                     "type": "github"
+                },
+                {
+                    "url": "https://liberapay.com/sebastianbergmann",
+                    "type": "liberapay"
+                },
+                {
+                    "url": "https://thanks.dev/u/gh/sebastianbergmann",
+                    "type": "thanks_dev"
+                },
+                {
+                    "url": "https://tidelift.com/funding/github/packagist/sebastian/recursion-context",
+                    "type": "tidelift"
                 }
             ],
-            "time": "2024-07-03T05:10:34+00:00"
+            "time": "2025-08-13T04:42:22+00:00"
         },
         {
             "name": "sebastian/type",
-            "version": "5.1.2",
+            "version": "5.1.3",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sebastianbergmann/type.git",
-                "reference": "a8a7e30534b0eb0c77cd9d07e82de1a114389f5e"
+                "reference": "f77d2d4e78738c98d9a68d2596fe5e8fa380f449"
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-                "url": "https://api.github.com/repos/sebastianbergmann/type/zipball/a8a7e30534b0eb0c77cd9d07e82de1a114389f5e",
-                "reference": "a8a7e30534b0eb0c77cd9d07e82de1a114389f5e",
+                "url": "https://api.github.com/repos/sebastianbergmann/type/zipball/f77d2d4e78738c98d9a68d2596fe5e8fa380f449",
+                "reference": "f77d2d4e78738c98d9a68d2596fe5e8fa380f449",
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@@ -2898,15 +2922,27 @@
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                 "security": "https://github.com/sebastianbergmann/type/security/policy",
-                "source": "https://github.com/sebastianbergmann/type/tree/5.1.2"
+                "source": "https://github.com/sebastianbergmann/type/tree/5.1.3"
             },
             "funding": [
                 {
                     "url": "https://github.com/sebastianbergmann",
                     "type": "github"
+                },
+                {
+                    "url": "https://liberapay.com/sebastianbergmann",
+                    "type": "liberapay"
+                },
+                {
+                    "url": "https://thanks.dev/u/gh/sebastianbergmann",
+                    "type": "thanks_dev"
+                },
+                {
+                    "url": "https://tidelift.com/funding/github/packagist/sebastian/type",
+                    "type": "tidelift"
                 }
             ],
-            "time": "2025-03-18T13:35:50+00:00"
+            "time": "2025-08-09T06:55:48+00:00"
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@@ -3016,16 +3052,16 @@
         },
         {
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-            "version": "v7.3.1",
+            "version": "v7.3.2",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/console.git",
-                "reference": "9e27aecde8f506ba0fd1d9989620c04a87697101"
+                "reference": "5f360ebc65c55265a74d23d7fe27f957870158a1"
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-                "url": "https://api.github.com/repos/symfony/console/zipball/9e27aecde8f506ba0fd1d9989620c04a87697101",
-                "reference": "9e27aecde8f506ba0fd1d9989620c04a87697101",
+                "url": "https://api.github.com/repos/symfony/console/zipball/5f360ebc65c55265a74d23d7fe27f957870158a1",
+                "reference": "5f360ebc65c55265a74d23d7fe27f957870158a1",
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@@ -3090,7 +3126,7 @@
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-                "source": "https://github.com/symfony/console/tree/v7.3.1"
+                "source": "https://github.com/symfony/console/tree/v7.3.2"
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             "funding": [
                 {
@@ -3101,12 +3137,16 @@
                     "url": "https://github.com/fabpot",
                     "type": "github"
                 },
+                {
+                    "url": "https://github.com/nicolas-grekas",
+                    "type": "github"
+                },
                 {
                     "url": "https://tidelift.com/funding/github/packagist/symfony/symfony",
                     "type": "tidelift"
                 }
             ],
-            "time": "2025-06-27T19:55:54+00:00"
+            "time": "2025-07-30T17:13:41+00:00"
         },
         {
             "name": "symfony/deprecation-contracts",
@@ -3333,16 +3373,16 @@
         },
         {
             "name": "symfony/filesystem",
-            "version": "v7.3.0",
+            "version": "v7.3.2",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/filesystem.git",
-                "reference": "b8dce482de9d7c9fe2891155035a7248ab5c7fdb"
+                "reference": "edcbb768a186b5c3f25d0643159a787d3e63b7fd"
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-                "url": "https://api.github.com/repos/symfony/filesystem/zipball/b8dce482de9d7c9fe2891155035a7248ab5c7fdb",
-                "reference": "b8dce482de9d7c9fe2891155035a7248ab5c7fdb",
+                "url": "https://api.github.com/repos/symfony/filesystem/zipball/edcbb768a186b5c3f25d0643159a787d3e63b7fd",
+                "reference": "edcbb768a186b5c3f25d0643159a787d3e63b7fd",
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             },
             "require": {
@@ -3379,7 +3419,7 @@
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             "homepage": "https://symfony.com",
             "support": {
-                "source": "https://github.com/symfony/filesystem/tree/v7.3.0"
+                "source": "https://github.com/symfony/filesystem/tree/v7.3.2"
             },
             "funding": [
                 {
@@ -3390,25 +3430,29 @@
                     "url": "https://github.com/fabpot",
                     "type": "github"
                 },
+                {
+                    "url": "https://github.com/nicolas-grekas",
+                    "type": "github"
+                },
                 {
                     "url": "https://tidelift.com/funding/github/packagist/symfony/symfony",
                     "type": "tidelift"
                 }
             ],
-            "time": "2024-10-25T15:15:23+00:00"
+            "time": "2025-07-07T08:17:47+00:00"
         },
         {
             "name": "symfony/finder",
-            "version": "v7.3.0",
+            "version": "v7.3.2",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/finder.git",
-                "reference": "ec2344cf77a48253bbca6939aa3d2477773ea63d"
+                "reference": "2a6614966ba1074fa93dae0bc804227422df4dfe"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/finder/zipball/ec2344cf77a48253bbca6939aa3d2477773ea63d",
-                "reference": "ec2344cf77a48253bbca6939aa3d2477773ea63d",
+                "url": "https://api.github.com/repos/symfony/finder/zipball/2a6614966ba1074fa93dae0bc804227422df4dfe",
+                "reference": "2a6614966ba1074fa93dae0bc804227422df4dfe",
                 "shasum": ""
             },
             "require": {
@@ -3443,7 +3487,7 @@
             "description": "Finds files and directories via an intuitive fluent interface",
             "homepage": "https://symfony.com",
             "support": {
-                "source": "https://github.com/symfony/finder/tree/v7.3.0"
+                "source": "https://github.com/symfony/finder/tree/v7.3.2"
             },
             "funding": [
                 {
@@ -3454,25 +3498,29 @@
                     "url": "https://github.com/fabpot",
                     "type": "github"
                 },
+                {
+                    "url": "https://github.com/nicolas-grekas",
+                    "type": "github"
+                },
                 {
                     "url": "https://tidelift.com/funding/github/packagist/symfony/symfony",
                     "type": "tidelift"
                 }
             ],
-            "time": "2024-12-30T19:00:26+00:00"
+            "time": "2025-07-15T13:41:35+00:00"
         },
         {
             "name": "symfony/options-resolver",
-            "version": "v7.3.0",
+            "version": "v7.3.2",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/options-resolver.git",
-                "reference": "afb9a8038025e5dbc657378bfab9198d75f10fca"
+                "reference": "119bcf13e67dbd188e5dbc74228b1686f66acd37"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/options-resolver/zipball/afb9a8038025e5dbc657378bfab9198d75f10fca",
-                "reference": "afb9a8038025e5dbc657378bfab9198d75f10fca",
+                "url": "https://api.github.com/repos/symfony/options-resolver/zipball/119bcf13e67dbd188e5dbc74228b1686f66acd37",
+                "reference": "119bcf13e67dbd188e5dbc74228b1686f66acd37",
                 "shasum": ""
             },
             "require": {
@@ -3510,7 +3558,7 @@
                 "options"
             ],
             "support": {
-                "source": "https://github.com/symfony/options-resolver/tree/v7.3.0"
+                "source": "https://github.com/symfony/options-resolver/tree/v7.3.2"
             },
             "funding": [
                 {
@@ -3521,12 +3569,16 @@
                     "url": "https://github.com/fabpot",
                     "type": "github"
                 },
+                {
+                    "url": "https://github.com/nicolas-grekas",
+                    "type": "github"
+                },
                 {
                     "url": "https://tidelift.com/funding/github/packagist/symfony/symfony",
                     "type": "tidelift"
                 }
             ],
-            "time": "2025-04-04T13:12:05+00:00"
+            "time": "2025-07-15T11:36:08+00:00"
         },
         {
             "name": "symfony/polyfill-ctype",
@@ -4211,16 +4263,16 @@
         },
         {
             "name": "symfony/string",
-            "version": "v7.3.0",
+            "version": "v7.3.2",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/string.git",
-                "reference": "f3570b8c61ca887a9e2938e85cb6458515d2b125"
+                "reference": "42f505aff654e62ac7ac2ce21033818297ca89ca"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/string/zipball/f3570b8c61ca887a9e2938e85cb6458515d2b125",
-                "reference": "f3570b8c61ca887a9e2938e85cb6458515d2b125",
+                "url": "https://api.github.com/repos/symfony/string/zipball/42f505aff654e62ac7ac2ce21033818297ca89ca",
+                "reference": "42f505aff654e62ac7ac2ce21033818297ca89ca",
                 "shasum": ""
             },
             "require": {
@@ -4278,7 +4330,7 @@
                 "utf8"
             ],
             "support": {
-                "source": "https://github.com/symfony/string/tree/v7.3.0"
+                "source": "https://github.com/symfony/string/tree/v7.3.2"
             },
             "funding": [
                 {
@@ -4289,12 +4341,16 @@
                     "url": "https://github.com/fabpot",
                     "type": "github"
                 },
+                {
+                    "url": "https://github.com/nicolas-grekas",
+                    "type": "github"
+                },
                 {
                     "url": "https://tidelift.com/funding/github/packagist/symfony/symfony",
                     "type": "tidelift"
                 }
             ],
-            "time": "2025-04-20T20:19:01+00:00"
+            "time": "2025-07-10T08:47:49+00:00"
         },
         {
             "name": "theseer/tokenizer",
@@ -4391,55 +4447,6 @@
                 "source": "https://github.com/wiz-develop/php-cs-fixer-config/tree/v8.4.0"
             },
             "time": "2025-07-16T08:44:26+00:00"
-        },
-        {
-            "name": "wiz-develop/php-value-object",
-            "version": "v0.5.8",
-            "source": {
-                "type": "git",
-                "url": "https://github.com/wiz-develop/php-value-object.git",
-                "reference": "2e460deaafc1a1c035f2535dd5866a008b729088"
-            },
-            "dist": {
-                "type": "zip",
-                "url": "https://api.github.com/repos/wiz-develop/php-value-object/zipball/2e460deaafc1a1c035f2535dd5866a008b729088",
-                "reference": "2e460deaafc1a1c035f2535dd5866a008b729088",
-                "shasum": ""
-            },
-            "require": {
-                "php": ">=8.4"
-            },
-            "require-dev": {
-                "phpstan/extension-installer": "^1.4",
-                "phpstan/phpstan": "^2.1",
-                "phpstan/phpstan-strict-rules": "^2.0",
-                "phpunit/php-code-coverage": "^11.0",
-                "phpunit/phpunit": "^11.3",
-                "wiz-develop/php-cs-fixer-config": "^8.3",
-                "wiz-develop/php-monad": "^2.2"
-            },
-            "type": "library",
-            "autoload": {
-                "psr-4": {
-                    "WizDevelop\\PhpValueObject\\": "src"
-                }
-            },
-            "notification-url": "https://packagist.org/downloads/",
-            "license": [
-                "MIT"
-            ],
-            "authors": [
-                {
-                    "name": "kakiuchi-shigenao",
-                    "email": "87973394+endou-mame@users.noreply.github.com"
-                }
-            ],
-            "description": "📦 The PHP Value Object library offers immutable, type-safe, and self-validating objects to model domain values using the Value Object pattern.",
-            "support": {
-                "issues": "https://github.com/wiz-develop/php-value-object/issues",
-                "source": "https://github.com/wiz-develop/php-value-object/tree/v0.5.8"
-            },
-            "time": "2025-05-12T08:55:46+00:00"
         }
     ],
     "aliases": [],
diff --git a/src/Result/functions.php b/src/Result/functions.php
index 2e40991..8551a49 100644
--- a/src/Result/functions.php
+++ b/src/Result/functions.php
@@ -8,7 +8,6 @@
 use Throwable;
 use WizDevelop\PhpMonad\Option;
 use WizDevelop\PhpMonad\Result;
-use WizDevelop\PhpValueObject\Error\IErrorValue;
 
 /**
  * Return a `Result\Ok` Result containing `$value`.
@@ -94,31 +93,13 @@ function transpose(Result $result): Option
 /**
  * @template T
  * @template E
- * @param  (Result<T, E>|Result)           ...$results
+ * @param  Result<covariant T, covariant E>                  ...$results
  * @return Result<bool, non-empty-list<E>>
  */
-function combine(Result ...$results): Result // @phpstan-ignore-line
+function combine(Result ...$results): Result
 {
     $errs = array_filter($results, static fn (Result $result) => $result->isErr());
     if (count($errs) > 0) {
-        // @phpstan-ignore return.type
-        return Result\err(array_values(array_map(static fn (Result $result) => $result->unwrapErr(), $errs)));
-    }
-
-    return Result\ok();
-}
-
-/**
- * @template T
- * @template E of IErrorValue
- * @param  (Result<T, E>|Result)           ...$results
- * @return Result<bool, non-empty-list<E>>
- */
-function combineWithErrorValue(Result ...$results): Result // @phpstan-ignore-line
-{
-    $errs = array_filter($results, static fn (Result $result) => $result->isErr());
-    if (count($errs) > 0) {
-        // @phpstan-ignore return.type
         return Result\err(array_values(array_map(static fn (Result $result) => $result->unwrapErr(), $errs)));
     }
 
diff --git a/tests/Unit/Result/CombineWithErrorValueTest.php b/tests/Unit/Result/CombineWithErrorValueTest.php
deleted file mode 100644
index 9660eaf..0000000
--- a/tests/Unit/Result/CombineWithErrorValueTest.php
+++ /dev/null
@@ -1,78 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace WizDevelop\PhpMonad\Tests\Unit\Result;
-
-use PHPUnit\Framework\Attributes\CoversClass;
-use PHPUnit\Framework\Attributes\Test;
-use PHPUnit\Framework\Attributes\TestDox;
-use WizDevelop\PhpMonad\Result;
-use WizDevelop\PhpMonad\Tests\Assert;
-use WizDevelop\PhpMonad\Tests\TestCase;
-use WizDevelop\PhpValueObject\Error\ErrorValue;
-
-#[TestDox('Result - combineWithErrorValue関数のテスト')]
-#[CoversClass(Result::class)]
-final class CombineWithErrorValueTest extends TestCase
-{
-    #[Test]
-    #[TestDox('すべてがOkの場合はOk(true)を返すcombineWithErrorValueのテスト')]
-    public function combineWithErrorValueAllOk(): void
-    {
-        $results = [
-            Result\ok(1),
-            Result\ok('test'),
-            Result\ok(true),
-        ];
-
-        $result = Result\combineWithErrorValue(...$results);
-
-        Assert::assertTrue($result->isOk());
-        Assert::assertTrue($result->unwrap());
-    }
-
-    #[Test]
-    #[TestDox('1つでもErrがある場合はErr(list<E>)を返すcombineWithErrorValueのテスト')]
-    public function combineWithErrorValueWithErrors(): void
-    {
-        $error1 = ErrorValue::of('error1', 'Error message 1');
-        $error2 = ErrorValue::of('error2', 'Error message 2');
-
-        $results = [
-            Result\ok(1),
-            Result\err($error1),
-            Result\ok(true),
-            Result\err($error2),
-            Result\ok('test'),
-        ];
-
-        $result = Result\combineWithErrorValue(...$results);
-
-        Assert::assertTrue($result->isErr());
-        $errors = $result->unwrapErr();
-        Assert::assertIsArray($errors);
-        Assert::assertCount(2, $errors);
-
-        // エラーの順序は配列のフィルタリング方法によって決まる
-        // 2つのエラーが含まれていることを確認
-        Assert::assertSame($error1, $errors[0]);
-        Assert::assertSame($error2, $errors[1]);
-
-        // エラーコードとメッセージが正しいことを確認
-        Assert::assertSame('error1', $errors[0]->getCode());
-        Assert::assertSame('Error message 1', $errors[0]->getMessage());
-        Assert::assertSame('error2', $errors[1]->getCode());
-        Assert::assertSame('Error message 2', $errors[1]->getMessage());
-    }
-
-    #[Test]
-    #[TestDox('空の配列を渡した場合はOk(true)を返すcombineWithErrorValueのテスト')]
-    public function combineWithErrorValueEmpty(): void
-    {
-        $result = Result\combineWithErrorValue();
-
-        Assert::assertTrue($result->isOk());
-        Assert::assertTrue($result->unwrap());
-    }
-}