diff --git a/src/Expression.cpp b/src/Expression.cpp
index 9b309dc..7caf860 100644
--- a/src/Expression.cpp
+++ b/src/Expression.cpp
@@ -21,6 +21,24 @@ string Expression::toString() {
 ExpressionBinary::ExpressionBinary(shared_ptr<Token> token, shared_ptr<Expression> left, shared_ptr<Expression> right):
     Expression(Expression::Kind::BINARY), left(left), right(right) {
     switch (token->getKind()) {
+        case Token::Kind::EQUAL:
+            operation = EQUAL;
+            break;
+        case Token::Kind::NOT_EQUAL:
+            operation = NOT_EQUAL;
+            break;
+        case Token::Kind::LESS:
+            operation = LESS;
+            break;
+        case Token::Kind::LESS_EQUAL:
+            operation = LESS_EQUAL;
+            break;
+        case Token::Kind::GREATER:
+            operation = GREATER;
+            break;
+        case Token::Kind::GREATER_EQUAL:
+            operation = GREATER_EQUAL;
+            break;
         case Token::Kind::PLUS:
             operation = ADD;
             break;
@@ -55,16 +73,28 @@ shared_ptr<Expression> ExpressionBinary::getRight() {
 
 string ExpressionBinary::toString() {
     switch (operation) {
+    case EQUAL:
+        return "{= " + left->toString() + " " + right->toString() + "}";
+    case NOT_EQUAL:
+        return "{!= " + left->toString() + " " + right->toString() + "}";
+    case LESS:
+        return "{< " + left->toString() + " " + right->toString() + "}";
+    case LESS_EQUAL:
+        return "{<= " + left->toString() + " " + right->toString() + "}";
+    case GREATER:
+        return "{> " + left->toString() + " " + right->toString() + "}";
+    case GREATER_EQUAL:
+        return "{<= " + left->toString() + " " + right->toString() + "}";
     case ADD:
-        return "<+ " + left->toString() + " " + right->toString() + ">";
+        return "{+ " + left->toString() + " " + right->toString() + "}";
     case SUB:
-        return "<- " + left->toString() + " " + right->toString() + ">";
+        return "{- " + left->toString() + " " + right->toString() + "}";
     case MUL:
-        return "<* " + left->toString() + " " + right->toString() + ">";
+        return "{* " + left->toString() + " " + right->toString() + "}";
     case DIV:
-        return "</ " + left->toString() + " " + right->toString() + ">";
+        return "{/ " + left->toString() + " " + right->toString() + "}";
     case MOD:
-        return "<% " + left->toString() + " " + right->toString() + ">";
+        return "{% " + left->toString() + " " + right->toString() + "}";
     }
 }
 
diff --git a/src/Expression.h b/src/Expression.h
index c5ad1e2..748ad95 100644
--- a/src/Expression.h
+++ b/src/Expression.h
@@ -47,6 +47,12 @@ public:
 class ExpressionBinary: public Expression {
 public:
     enum Operation {
+        EQUAL,
+        NOT_EQUAL,
+        LESS,
+        LESS_EQUAL,
+        GREATER,
+        GREATER_EQUAL,
         ADD,
         SUB,
         MUL,
diff --git a/src/Lexer.cpp b/src/Lexer.cpp
index 507cdda..8fb6f4d 100644
--- a/src/Lexer.cpp
+++ b/src/Lexer.cpp
@@ -120,7 +120,7 @@ shared_ptr<Token> Lexer::nextToken() {
     if (token != nullptr)
         return token;
     
-    // logical
+    // comparison
     token = match(Token::Kind::NOT_EQUAL, "!=", false);
     if (token != nullptr)
         return token;
diff --git a/src/Parser.cpp b/src/Parser.cpp
index 3409f02..36d0f0a 100644
--- a/src/Parser.cpp
+++ b/src/Parser.cpp
@@ -122,7 +122,33 @@ shared_ptr<StatementInvalid> Parser::matchStatementInvalid() {
 // Expression
 //
 shared_ptr<Expression> Parser::nextExpression() {
-    return matchTerm();
+    return matchEquality();
+}
+
+shared_ptr<Expression> Parser::matchEquality() {
+    shared_ptr<Expression> expression = matchTerm();
+    if (expression == nullptr || !expression->isValid())
+        return expression;
+
+    while (tokens.at(currentIndex)->isOfKind(Token::tokensEquality)) {
+        // comaprison
+        expression = matchExpressionBinary(expression);
+    }
+
+    return expression;
+}
+
+shared_ptr<Expression> Parser::matchComparison() {
+    shared_ptr<Expression> expression = matchTerm();
+    if (expression == nullptr || !expression->isValid())
+        return expression;
+    
+    while (tokens.at(currentIndex)->isOfKind(Token::tokensComparison)) {
+        // term
+        expression = matchExpressionBinary(expression);
+    }
+    
+    return expression;
 }
 
 shared_ptr<Expression> Parser::matchTerm() {
@@ -130,7 +156,8 @@ shared_ptr<Expression> Parser::matchTerm() {
     if (expression == nullptr || !expression->isValid())
         return expression;
 
-    while (tokens.at(currentIndex)->isOfKind({Token::Kind::PLUS, Token::Kind::MINUS})) {
+    while (tokens.at(currentIndex)->isOfKind(Token::tokensTerm)) {
+        // factor
         expression = matchExpressionBinary(expression);
     }
 
@@ -142,7 +169,8 @@ shared_ptr<Expression> Parser::matchFactor() {
     if (expression == nullptr || !expression->isValid())
         return expression;
 
-    while (tokens.at(currentIndex)->isOfKind({Token::Kind::STAR, Token::Kind::SLASH, Token::Kind::PERCENT})) {
+    while (tokens.at(currentIndex)->isOfKind(Token::tokensFactor)) {
+        // unary
         expression = matchExpressionBinary(expression);
     }
 
@@ -196,7 +224,7 @@ shared_ptr<Expression> Parser::matchExpressionGrouping() {
 
 shared_ptr<Expression> Parser::matchExpressionBinary(shared_ptr<Expression> left) {
     shared_ptr<Token> token = tokens.at(currentIndex);
-    if (token->isOfKind({Token::Kind::PLUS, Token::Kind::MINUS, Token::Kind::STAR, Token::Kind::SLASH, Token::Kind::PERCENT})) {
+    if (token->isOfKind(Token::tokensBinary)) {
         currentIndex++;
         shared_ptr<Expression> right = matchFactor();
         if (right == nullptr) {
diff --git a/src/Parser.h b/src/Parser.h
index 22e19fe..054b130 100644
--- a/src/Parser.h
+++ b/src/Parser.h
@@ -22,6 +22,8 @@ private:
     shared_ptr<StatementInvalid> matchStatementInvalid();
 
     shared_ptr<Expression> nextExpression();
+    shared_ptr<Expression> matchEquality(); // =, !=
+    shared_ptr<Expression> matchComparison(); // <, <=, >, >=
     shared_ptr<Expression> matchTerm(); // +, -
     shared_ptr<Expression> matchFactor(); // *, /, %
     shared_ptr<Expression> matchPrimary(); // integer, ()
diff --git a/src/Token.cpp b/src/Token.cpp
index b8b6948..4baa857 100644
--- a/src/Token.cpp
+++ b/src/Token.cpp
@@ -1,5 +1,41 @@
 #include "Token.h"
 
+vector<Token::Kind> Token::tokensEquality = {
+    Token::Kind::EQUAL,
+    Token::Kind::NOT_EQUAL
+};
+vector<Token::Kind> Token::tokensComparison = {
+    Token::Kind::LESS,
+    Token::Kind::LESS_EQUAL,
+    Token::Kind::GREATER,
+    Token::Kind::GREATER_EQUAL
+};
+vector<Token::Kind> Token::tokensTerm = {
+    Token::Kind::PLUS,
+    Token::Kind::MINUS
+};
+vector<Token::Kind> Token::tokensFactor = {
+    Token::Kind::STAR,
+    Token::Kind::SLASH,
+    Token::Kind::PERCENT
+};
+vector<Token::Kind> Token::tokensBinary = {
+    Token::Kind::EQUAL,
+    Token::Kind::NOT_EQUAL,
+
+    Token::Kind::LESS,
+    Token::Kind::LESS_EQUAL,
+    Token::Kind::GREATER,
+    Token::Kind::GREATER_EQUAL,
+
+    Token::Kind::PLUS,
+    Token::Kind::MINUS,
+    
+    Token::Kind::STAR,
+    Token::Kind::SLASH,
+    Token::Kind::PERCENT
+};
+
 Token::Token(Kind kind, string lexme, int line, int column):
     kind(kind), lexme(lexme), line(line), column(column) {
 }
diff --git a/src/Token.h b/src/Token.h
index 1f32570..8d91da6 100644
--- a/src/Token.h
+++ b/src/Token.h
@@ -45,6 +45,12 @@ private:
     int column;
 
 public:
+    static vector<Token::Kind> tokensEquality;
+    static vector<Token::Kind> tokensComparison;
+    static vector<Token::Kind> tokensTerm;
+    static vector<Token::Kind> tokensFactor;
+    static vector<Token::Kind> tokensBinary;
+
     Token(Kind kind, string lexme, int line, int column);
     Kind getKind();
     string getLexme();