diff --git a/src/nso_ba.h b/src/nso_ba.h
index f8a1a27..e1baba1 100644
--- a/src/nso_ba.h
+++ b/src/nso_ba.h
@@ -7,82 +7,154 @@
 
 namespace idni::tau_lang {
 
+/**
+ * @brief Bitwise AND operator for tau.
+ * @param l Left-hand side operand.
+ * @param r Right-hand side operand.
+ * @return Result of bitwise AND operation.
+ */
 template <typename... BAs>
-tau<BAs...> operator&(const tau<BAs...>& l,	const tau<BAs...>& r);
-
+tau<BAs...> operator&(const tau<BAs...>& l, const tau<BAs...>& r);
+
+/**
+ * @brief Bitwise OR operator for tau.
+ * @param l Left-hand side operand.
+ * @param r Right-hand side operand.
+ * @return Result of bitwise OR operation.
+ */
 template <typename... BAs>
 tau<BAs...> operator|(const tau<BAs...>& l, const tau<BAs...>& r);
 
+/**
+ * @brief Bitwise NOT operator for tau.
+ * @param l Operand.
+ * @return Result of bitwise NOT operation.
+ */
 template <typename... BAs>
 tau<BAs...> operator~(const tau<BAs...>& l);
 
+/**
+ * @brief Bitwise XOR operator for tau.
+ * @param l Left-hand side operand.
+ * @param r Right-hand side operand.
+ * @return Result of bitwise XOR operation.
+ */
 template <typename... BAs>
 tau<BAs...> operator^(const tau<BAs...>& l, const tau<BAs...>& r);
 
+/**
+ * @brief Addition operator for tau.
+ * @param l Left-hand side operand.
+ * @param r Right-hand side operand.
+ * @return Result of addition operation.
+ */
 template <typename... BAs>
 tau<BAs...> operator+(const tau<BAs...>& l, const tau<BAs...>& r);
 
+/**
+ * @brief Checks if the tau is zero.
+ * @param l Operand.
+ * @return True if the tau is zero, false otherwise.
+ */
 template <typename... BAs>
 bool is_zero(const tau<BAs...>& l);
 
+/**
+ * @brief Checks if the tau is one.
+ * @param l Operand.
+ * @return True if the tau is one, false otherwise.
+ */
 template <typename... BAs>
 bool is_one(const tau<BAs...>& l);
 
-// We overload the == operator for tau in order to store additional data
-// which is not taken into account for the quality check
+/**
+ * @brief Equality operator for tau.
+ * @param l Left-hand side operand.
+ * @param r Right-hand side operand.
+ * @return True if both tau are equal, false otherwise.
+ */
 template <typename... BAs>
-bool operator==(const tau<BAs...> &l, const tau<BAs...>& r);
-
+bool operator==(const tau<BAs...>& l, const tau<BAs...>& r);
+
+/**
+ * @brief Inequality operator for tau.
+ * @param l Left-hand side operand.
+ * @param r Right-hand side operand.
+ * @return True if both tau are not equal, false otherwise.
+ */
 template <typename... BAs>
 bool operator!=(const tau<BAs...>& l, const tau<BAs...>& r);
 
+/**
+ * @brief Three-way comparison operator for tau.
+ * @param l Left-hand side operand.
+ * @param r Right-hand side operand.
+ * @return Result of the three-way comparison.
+ */
 template <typename... BAs>
 std::weak_ordering operator<=>(const tau<BAs...>& l, const tau<BAs...>& r);
 
+/**
+ * @brief Less-than operator for tau.
+ * @param l Left-hand side operand.
+ * @param r Right-hand side operand.
+ * @return True if l is less than r, false otherwise.
+ */
 template<typename... BAs>
 bool operator<(const tau<BAs...>& l, const tau<BAs...>& r);
 
+/**
+ * @brief Less-than or equal-to operator for tau.
+ * @param l Left-hand side operand.
+ * @param r Right-hand side operand.
+ * @return True if l is less than or equal to r, false otherwise.
+ */
 template<typename... BAs>
 bool operator<=(const tau<BAs...>& l, const tau<BAs...>& r);
 
+/**
+ * @brief Greater-than operator for tau.
+ * @param l Left-hand side operand.
+ * @param r Right-hand side operand.
+ * @return True if l is greater than r, false otherwise.
+ */
 template<typename... BAs>
 bool operator>(const tau<BAs...>& l, const tau<BAs...>& r);
 
+/**
+ * @brief Greater-than or equal-to operator for tau.
+ * @param l Left-hand side operand.
+ * @param r Right-hand side operand.
+ * @return True if l is greater than or equal to r, false otherwise.
+ */
 template<typename... BAs>
 bool operator>=(const tau<BAs...>& l, const tau<BAs...>& r);
 
+/**
+ * @brief Equality operator for tau and bool.
+ * @param l Left-hand side operand.
+ * @param r Right-hand side operand.
+ * @return True if tau is equal to the boolean value, false otherwise.
+ */
 template <typename... BAs>
 bool operator==(const tau<BAs...>& l, const bool& r);
 
+/**
+ * @brief Equality operator for bool and tau.
+ * @param l Left-hand side operand.
+ * @param r Right-hand side operand.
+ * @return True if boolean value is equal to tau, false otherwise.
+ */
 template <typename... BAs>
 bool operator==(const bool l, const tau<BAs...>& r);
 
-// Splitter function for a nso tau_parser::bf_constant node holding a BA constant
+/**
+ * @brief Splitter function for a nso tau_parser::bf_constant node holding a BA constant.
+ * @param n Operand.
+ * @param st Splitter type (default is splitter_type::upper).
+ * @return Result of the splitter operation.
+ */
 template <typename... BAs>
 tau<BAs...> splitter(const tau<BAs...>& n, splitter_type st = splitter_type::upper);
 
-} // namespace idni::tau_lang
-
-
-template <typename... BAs>
-std::ostream& operator<<(std::ostream& stream,
-	const idni::tau_lang::tau<BAs...>& n);
-
-// << for node<tau_sym>
-template <typename... BAs>
-std::ostream& operator<<(std::ostream& stream,
-	const idni::rewriter::node<idni::tau_lang::tau_sym<BAs...>>& n);
-
-
-// outputs a sp_tau_source_node to a stream, using the stringify transformer
-// and assumes that the constants also override operator<<.
-std::ostream& operator<<(std::ostream& stream,
-			const idni::tau_lang::sp_tau_source_node& n);
-
-// << tau_source_node (make it shared to make use of the previous operator)
-std::ostream& operator<<(std::ostream& stream,
-					const idni::tau_lang::tau_source_node& n);
-
-#include "nso_ba.tmpl.h"
-
-#endif // __NSO_BA_H__
\ No newline at end of file
+} // namespace idni::tau_lang
\ No newline at end of file