diff --git a/parser/Cargo.toml b/parser/Cargo.toml
index 110049f..5475a2c 100644
--- a/parser/Cargo.toml
+++ b/parser/Cargo.toml
@@ -4,6 +4,7 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+chumsky = "0.10.1"
 logos = "0.15.0"
 rowan = "0.16.1"
 thiserror = "2.0.12"
diff --git a/parser/src/parser/ast.rs b/parser/src/parser/ast.rs
index 424d95c..b3a3170 100644
--- a/parser/src/parser/ast.rs
+++ b/parser/src/parser/ast.rs
@@ -59,6 +59,9 @@ pub enum SyntaxKind {
     GROUP_BY,
 
     CREATE,
+    ALTER,
+    DROP,
+    TRUNCATE,
 
     TABLE,
 
@@ -72,11 +75,21 @@ pub enum SyntaxKind {
     PARENTHESES_END,
     VALUES,
     DEFINITION,
+
     EQUAL,
     GT,
     LT,
+    LEQT,
+    GEQT,
+
     AND,
     OR,
+    NOT,
+
+    TRUE,
+    FALSE,
+    BOOLEAN_OP,
+
     GROUP,
     ORDER,
     BY,
@@ -84,19 +97,22 @@ pub enum SyntaxKind {
     ASC,
     DISTINCT,
 
-    COMPARE,
-    GREATER,
-    LESS,
+    COMPARISON,
     EMPTY,
     ROOT,
 }
 
 impl SyntaxKind {
     pub fn is_dql(&self) -> bool {
-        (2..=3).contains(&(*self as u16))
+        //(2..=3).contains(&(*self as u16))
+        *self == SELECT
     }
     pub fn is_ddl(&self) -> bool {
-        (4..=4).contains(&(*self as u16))
+        //(4..=4).contains(&(*self as u16))
+        match *self {
+            CREATE | ALTER | DROP | TRUNCATE => true,
+            _ => false,
+        }
     }
 }
 
diff --git a/parser/src/parser/ast/ast_trait.rs b/parser/src/parser/ast/ast_trait.rs
new file mode 100644
index 0000000..bf6bb36
--- /dev/null
+++ b/parser/src/parser/ast/ast_trait.rs
@@ -0,0 +1,36 @@
+use crate::parser::ast::ast::SyntaxKind;
+use crate::parser::ast::errors::AstErr;
+use crate::parser::lexer::Token;
+use std::fmt::Display;
+
+pub trait AstNode: Display + Eq {
+    fn add_child<A>(&mut self, child: &A) -> Result<(), AstErr>
+    where
+        A: AstNode;
+    fn is_compatible<A>(&self, child: &A) -> Result<(), AstErr>
+    where
+        A: AstNode;
+    fn get_parent<A>(&self) -> Option<A>
+    where
+        A: AstNode;
+    fn get_kind<A>(&self) -> SyntaxKind;
+}
+
+pub trait AstToken: AstNode {
+    fn get_token(&self) -> Token;
+}
+
+pub trait AstNodeContainer: AstNode {
+    fn get_children<A>(&self) -> Vec<Box<A>>
+    where
+        A: AstNode;
+}
+
+pub trait Ast<N>: Iterator
+where
+    N: AstNode,
+{
+    fn diff(&self, other: &Self) -> Self;
+    fn as_node(&self) -> N;
+    fn from(root: &N) -> Self;
+}
diff --git a/parser/src/parser/ast/errors.rs b/parser/src/parser/ast/errors.rs
new file mode 100644
index 0000000..b70f72f
--- /dev/null
+++ b/parser/src/parser/ast/errors.rs
@@ -0,0 +1,4 @@
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum AstErr {}
diff --git a/parser/src/parser/ast/mod.rs b/parser/src/parser/ast/mod.rs
new file mode 100644
index 0000000..aef3a4e
--- /dev/null
+++ b/parser/src/parser/ast/mod.rs
@@ -0,0 +1,5 @@
+pub mod ast;
+pub mod ast_trait;
+pub mod errors;
+pub mod nodes;
+pub mod operators;
diff --git a/parser/src/parser/lexer.rs b/parser/src/parser/lexer.rs
index 06a4751..944308d 100644
--- a/parser/src/parser/lexer.rs
+++ b/parser/src/parser/lexer.rs
@@ -27,6 +27,9 @@ pub enum Token {
     #[regex("(?i)OR")]
     Or,
 
+    #[regex("(?i)NOT")]
+    Not,
+
     #[regex("(?i)GROUP")]
     Group,
 
@@ -66,6 +69,12 @@ pub enum Token {
     #[token("=")]
     Equal,
 
+    #[token(">=")]
+    GEQT,
+
+    #[token("<=")]
+    LEQT,
+
     #[token(">")]
     GT,
 
@@ -104,8 +113,11 @@ impl Token {
             Token::Where => (SyntaxKind::WHERE, String::from("WHERE")),
             Token::LT => (SyntaxKind::LT, String::from("<")),
             Token::GT => (SyntaxKind::GT, String::from(">")),
+            Token::LEQT => (SyntaxKind::LT, String::from("<=")),
+            Token::GEQT => (SyntaxKind::GT, String::from(">=")),
             Token::And => (SyntaxKind::AND, String::from("AND")),
             Token::Or => (SyntaxKind::OR, String::from("OR")),
+            Token::Not => (SyntaxKind::NOT, String::from("NOT")),
             Token::Group => (SyntaxKind::GROUP, String::from("GROUP")),
             Token::By => (SyntaxKind::BY, String::from("BY")),
             Token::Desc => (SyntaxKind::DESC, String::from("DESC")),
diff --git a/parser/src/parser/sql/group_by.rs b/parser/src/parser/sql/group_by.rs
index 4feab9e..9c78e05 100644
--- a/parser/src/parser/sql/group_by.rs
+++ b/parser/src/parser/sql/group_by.rs
@@ -1,6 +1,4 @@
 use crate::parser::ast::SyntaxKind::*;
 use crate::parser::grammar::Grammar::{self, *};
-use crate::parser::grammar::GrammarType::*;
 
-pub const GROUP_BY_GRAMMAR: Grammar =
-    Children(&[GROUP, BY], GROUP_BY, &[List(&[IDENTIFIER])]);
+pub const GROUP_BY_GRAMMAR: Grammar = Children(&[GROUP, BY], GROUP_BY, &[List(&[IDENTIFIER])]);