+/** Automorphism of the Clifford algebra, simply changes signs of all
+ * clifford units. */
+ex clifford_prime(const ex & e);
+
+/** Main anti-automorphism of the Clifford algebra: makes reversion
+ * and changes signs of all clifford units. */
+inline ex clifford_bar(const ex & e) { return clifford_prime(e.conjugate()); }
+
+/** Reversion of the Clifford algebra, coincides with the conjugate(). */
+inline ex clifford_star(const ex & e) { return e.conjugate(); }
+
+ex delete_ONE(const ex &e);
+
+/** Calculation of the norm in the Clifford algebra. */
+ex clifford_norm(const ex & e);
+
+/** Calculation of the inverse in the Clifford algebra. */
+ex clifford_inverse(const ex & e);
+
+/** List or vector conversion into the Clifford vector.
+ *
+ * @param v List or vector of coordinates
+ * @param mu Index (must be of class varidx or a derived class)
+ * @param metr Metric (should be of class tensmetric or a derived class, or a symmetric matrix)
+ * @param rl Representation label
+ * @return Clifford vector with given components */
+ex lst_to_clifford(const ex & v, const ex & mu, const ex & metr, unsigned char rl = 0);
+