diff --git a/src/include/parser.h b/src/include/parser.h
new file mode 100644
index 0000000..c4d54d9
--- /dev/null
+++ b/src/include/parser.h
@@ -0,0 +1,74 @@
+#ifndef DEF_PARSER_H
+#define DEF_PARSER_H
+
+#include "tokenize.h"
+using namespace std;
+
+/** Grammar:
+Prog -> Instruction; Prog | \epsilon
+
+Instruction -> Statement | ExprStatement | Expr
+
+Statement -> // Rien pour l'instant, mais "for", "if" etc
+ExprStatement -> 
+    | Type Identifier = Expr // AssignedDeclaration
+    | Type Identifier // Declaration
+
+
+Expr ->
+    | T
+    | T + S
+    | T - S
+
+T ->
+    | F
+    | F * T
+    | F / T
+    | F % T
+
+F ->
+    | U
+    | - F
+    | + F
+
+U ->
+    | (Expr)
+    | Identifier
+    | Number
+    | Identifier = Expr // Assignment
+*/
+
+enum class NodeType {
+    Prog, //                  -> Instruction; Prog
+    AssignedDeclaration, //   -> Type Identifier = Expr
+    Declaration, //           -> Type Identifier
+    Plus, //                  -> T + S
+    Minus, //                 -> T - S
+    Mult, //                  -> F * T
+    Div, //                   -> F / T
+    Mod, //                   -> F % T
+    UnaryMinus, //            -> -F
+    UnaryPlus, //             -> +F
+    Parenthesis, //           -> (Expr)
+    Assignment, //            -> Identifier = Expr
+    Leaf
+};
+
+struct Node {
+    NodeType type;
+    Node* children;
+};
+
+
+// A Leaf is always corresponding to a Token
+enum class TreeType { Leaf, Node };
+struct SyntaxTree {
+    TreeType type;
+    union {
+        Node node;
+        Token leaf;
+    };
+};
+
+
+#endif
\ No newline at end of file