“…This approach can be generalized to situations where the representation does not necessarily lie on a straight line: see in particular the papers of Golomb [22] and Giles [19,20,21] where fixed points of morphisms and automatic sequences are not mentioned but can be found, and the papers of Dekking [9,10,11]. In the same direction see the papers of Dekking, Dekking and Mendès France, Deshouillers, Mendès France, and Mendès France and Shallit [12,13,15,29,30], but also the paper of Salon with an appendix by Shallit [32], where two-dimensional automatic sequences enter the picture, without forgetting the article by Prusinkiewicz and Hammel [31], and the article by Allouche, Allouche and Shallit [2]. We would also like to quote two papers by von Haeseler, Peitgen, Skordev [23,24] and the references therein, and a paper by Barbé and von Haeseler [5].…”