diff --git a/package-lock.json b/package-lock.json
index 23e74c5..d6bd39a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "@scicave/math-parser",
-  "version": "2.2.0",
+  "version": "2.2.1",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
diff --git a/package.json b/package.json
index 8c70378..a5693cb 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@scicave/math-parser",
-  "version": "2.2.0",
+  "version": "2.2.1",
   "description": "A mathematical parser. We mean by mathematical that, e.g., arithmetic operations is considered for example if you pass \"1+2\", the result would by a (add node \"+\") with two children nodes of type number.",
   "main": "lib/index.js",
   "files": [
diff --git a/src/version.js b/src/version.js
index d00eb2e..6836a24 100644
--- a/src/version.js
+++ b/src/version.js
@@ -1,4 +1,4 @@
 
 // this file is auto generated
 // the current version is:
-module.exports = "2.2.0";
+module.exports = "2.2.1";
diff --git a/tools/build.js b/tools/build.js
index ac21e15..37ff8b5 100644
--- a/tools/build.js
+++ b/tools/build.js
@@ -1,105 +1,105 @@
-const pegjs = require("pegjs");
-const fs = require("fs");
-const path = require("path");
-const rimraf = require("rimraf");
-
-let dev = process.env.NODE_ENV !== "production";
-
-let pegjsOptions = {
-  output: "source",
-  format: "commonjs",
-};
-
-let replacements = [
-  {
-    text: [
-      "module.exports = {",
-      "  SyntaxError: peg$SyntaxError,",
-      "  parse:       peg$parse", "};"
-    ].join("\n"),
-
-    replacement: [
-      "module.exports = {",
-      "  SyntaxError: peg$SyntaxError,",
-      "  parse:       peg$parse,",
-      "  Node,", "  version,",
-      "};"
-    ].join("\n"),
-  },
-];
-
-let grammarFiles = [
-  {
-    input: "../src/math.pegjs",
-    output: "../lib/index.js",
-    dependencies: {
-      Node: "./mathParserNode.js",
-      version: "./version.js",
-    },
-  },
-];
-
-grammarFiles.forEach((file) => {
-  pegjsOptions.dependencies = file.dependencies;
-  let inputPath = path.resolve(__dirname, file.input);
-  let inputDir = path.dirname(inputPath);
-  let outputPath = path.resolve(__dirname, file.output);
-  let outputDir = path.dirname(outputPath);
-
-  if (outputDir !== inputDir) {
-    prepareOutputDir(outputDir);
-  }
-
-  console.log("compiling>>>>>>>>>>>>>");
-  console.log(inputPath);
-  console.log();
-
-  function getParserCode() {
-    let grammar = fs.readFileSync(inputPath).toString("utf8");
-    let code = pegjs.generate(grammar, pegjsOptions);
-
-    /// some targeted replacments
-    for (let r of replacements) {
-      code = code.replace(r.text, r.replacement);
-    }
-
-    /// here we want to replace comment with contents file
-    code = code.replace(/\/\*\*#\s*require\s*\(\s*"(.*?)"\s*\)\s*\*\//gm, (m, g) => {
-      return fs.readFileSync(path.resolve(inputDir, g)).toString("utf8");
-    });
-
-    return code;
-  }
-
-  fs.writeFileSync(outputPath, getParserCode());
-
-  if (outputDir !== inputDir) {
-    // copy depedencies to the output directory
-    for (let d of Object.values(file.dependencies)) {
-      let p1 = path.resolve(inputDir, d);
-      let p2 = path.resolve(outputDir, d);
-      let dist = path.dirname(p2);
-
-      if (!fs.existsSync(dist)) {
-        fs.mkdirSync(dist, { recursive: true });
-      }
-
-      let readable = fs.createReadStream(p1, { encoding: "utf-8" });
-      let writable = fs.createWriteStream(p2);
-      readable.pipe(writable);
-    }
-  }
-
-  console.log("js code:::::::::");
-  console.log(outputPath);
-  console.log();
-});
-
-function prepareOutputDir(outputDir) {
-  if (fs.existsSync(outputDir)) {
-    /// delete all the output dir content
-    rimraf.sync(path.resolve(outputDir, "*"));
-  } else {
-    fs.mkdirSync(outputDir, { recursive: true });
-  }
-}
+const pegjs = require("pegjs");
+const fs = require("fs");
+const path = require("path");
+const rimraf = require("rimraf");
+
+let dev = process.env.NODE_ENV !== "production";
+
+let pegjsOptions = {
+  output: "source",
+  format: "commonjs",
+};
+
+let replacements = [
+  {
+    text: [
+      "module.exports = {",
+      "  SyntaxError: peg$SyntaxError,",
+      "  parse:       peg$parse", "};"
+    ].join("\n"),
+
+    replacement: [
+      "module.exports = {",
+      "  SyntaxError: peg$SyntaxError,",
+      "  parse:       peg$parse,",
+      "  Node,", "  version,",
+      "};"
+    ].join("\n"),
+  },
+];
+
+let grammarFiles = [
+  {
+    input: "../src/math.pegjs",
+    output: "../lib/index.js",
+    dependencies: {
+      Node: "./mathParserNode.js",
+      version: "./version.js",
+    },
+  },
+];
+
+grammarFiles.forEach((file) => {
+  pegjsOptions.dependencies = file.dependencies;
+  let inputPath = path.resolve(__dirname, file.input);
+  let inputDir = path.dirname(inputPath);
+  let outputPath = path.resolve(__dirname, file.output);
+  let outputDir = path.dirname(outputPath);
+
+  if (outputDir !== inputDir) {
+    prepareOutputDir(outputDir);
+  }
+
+  console.log("compiling>>>>>>>>>>>>>");
+  console.log(inputPath);
+  console.log();
+
+  function getParserCode() {
+    let grammar = fs.readFileSync(inputPath).toString("utf8");
+    let code = pegjs.generate(grammar, pegjsOptions);
+
+    /// some targeted replacments
+    for (let r of replacements) {
+      code = code.replace(r.text, r.replacement);
+    }
+
+    /// here we want to replace comment with contents file
+    code = code.replace(/\/\*\*#\s*require\s*\(\s*"(.*?)"\s*\)\s*\*\//gm, (m, g) => {
+      return fs.readFileSync(path.resolve(inputDir, g)).toString("utf8");
+    });
+
+    return code;
+  }
+
+  fs.writeFileSync(outputPath, getParserCode());
+
+  if (outputDir !== inputDir) {
+    // copy depedencies to the output directory
+    for (let d of Object.values(file.dependencies)) {
+      let p1 = path.resolve(inputDir, d);
+      let p2 = path.resolve(outputDir, d);
+      let dist = path.dirname(p2);
+
+      if (!fs.existsSync(dist)) {
+        fs.mkdirSync(dist, { recursive: true });
+      }
+
+      let readable = fs.createReadStream(p1, { encoding: "utf-8" });
+      let writable = fs.createWriteStream(p2);
+      readable.pipe(writable);
+    }
+  }
+
+  console.log("js code:::::::::");
+  console.log(outputPath);
+  console.log();
+});
+
+function prepareOutputDir(outputDir) {
+  if (fs.existsSync(outputDir)) {
+    /// delete all the output dir content
+    rimraf.sync(path.resolve(outputDir, "*"));
+  } else {
+    fs.mkdirSync(outputDir, { recursive: true });
+  }
+}
diff --git a/tools/generate-version-file.js b/tools/generate-version-file.js
index ebd22a0..97eba3e 100644
--- a/tools/generate-version-file.js
+++ b/tools/generate-version-file.js
@@ -1,14 +1,14 @@
-let pkg = require('../package.json');
-let filePath = '../src/version.js'; 
-let version = pkg.version;
-let path = require('path');
-let fs = require('fs');
-
-let code =`
-// this file is auto generated
-// the current version is:
-module.exports = "${version}";
-`;
-
-fs.writeFileSync(path.resolve(__dirname, filePath), code);
-
+let pkg = require('../package.json');
+let filePath = '../src/version.js'; 
+let version = pkg.version;
+let path = require('path');
+let fs = require('fs');
+
+let code =`
+// this file is auto generated
+// the current version is:
+module.exports = "${version}";
+`;
+
+fs.writeFileSync(path.resolve(__dirname, filePath), code);
+