+/* Return true if MAT is an identity matrix. */
+
+bool
+lambda_trans_matrix_id_p (lambda_trans_matrix mat)
+{
+ if (LTM_ROWSIZE (mat) != LTM_COLSIZE (mat))
+ return false;
+ return lambda_matrix_id_p (LTM_MATRIX (mat), LTM_ROWSIZE (mat));
+}
+
+
+/* Compute the inverse of the transformation matrix MAT. */