diff --git a/ast/include/ast/ast_raw_structs.h b/ast/include/ast/ast_raw_structs.h
index 55b73e8b..dccfe6cc 100644
--- a/ast/include/ast/ast_raw_structs.h
+++ b/ast/include/ast/ast_raw_structs.h
@@ -6,7 +6,7 @@
 /*   By: maiboyer <maiboyer@student.42.fr>          +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2024/06/14 17:46:58 by maiboyer          #+#    #+#             */
-/*   Updated: 2024/07/20 16:28:03 by maiboyer         ###   ########.fr       */
+/*   Updated: 2024/07/21 15:29:33 by rparodi          ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -388,7 +388,7 @@ struct s_ast_heredoc_redirection
 /// 	$@
 /// ```
 
-struct s_ast_expansion
+struct  s_ast_expansion
 {
 	t_str						var_name;
 	bool						len_operator;
@@ -409,6 +409,14 @@ struct s_ast_arithmetic_expansion
 	t_ast_node	expr;
 };
 
+struct s_ast_binary_op
+{
+	t_ast_node	operator;
+};
+
+{
+	t_ast_node	expr;
+};
 /// Command Substitution
 /// ```shell
 /// 	$(command)
diff --git a/ast/src/from_node.c b/ast/src/from_node.c
index 5f89e35d..50c8fe0b 100644
--- a/ast/src/from_node.c
+++ b/ast/src/from_node.c
@@ -1,8 +1,3 @@
-/* ************************************************************************** */
-/*                                                                            */
-/*                                                        :::      ::::::::   */
-/*   from_node.c                                        :+:      :+:    :+:   */
-/*                                                    +:+ +:+         +:+     */
 /*   By: maiboyer <maiboyer@student.42.fr>          +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2024/06/17 12:41:56 by maiboyer          #+#    #+#             */
@@ -72,6 +67,8 @@ sym_while_statement
 sym_word
 */
 
+#include <ctype.h>
+#include <inttypes.h>
 #include <stdio.h>
 
 #undef ERROR
@@ -618,6 +615,29 @@ t_error build_sym_heredoc_start(t_parse_node self, t_const_str input, t_ast_node
 
 #include <stdio.h>
 
+t_error build_sym_arithmetic_binary_expression(t_parse_node self, t_const_str input, t_ast_node *out);
+{
+	t_usize		i;
+	t_ast_node	*ret;
+
+	i = 0;
+	ret = ast_alloc(AST_ARITHMETIC_EXPANSION);
+	while (str[i] == '\0')
+	{
+		if (str[i] == '+')
+			ret->operator = '+';
+		if (str[i] == '-')
+			ret->operator = '-';
+		if (str[i] == '/')
+			ret->operator = '/';
+		if (str[i] == '%')
+			ret->operator = '%';
+		if (str[i] == '*')
+			ret->operator = '*';
+	}
+	 
+}
+
 t_error build_sym_command_substitution(t_parse_node self, t_const_str input, t_ast_node *out)
 {
 	t_ast_node ret;