  On the basis of an extended notion of sign, the authors of late 15th- and early 16th-century logic discussed at length topics like the different kinds of signification and representation (Gaspar Lax, Parve divis. term., ca. 1502, fol. a5[55]  or the traditional distinction of natural and conventional signs, showing that there exist intermediate forms, like those signs that signify by custom (ex consuetudine) (Hagenau, Comment. in prim. et quart. tract. Petri Hisp, 1495, fol. a7v; Conrad Pschlacher, Compendiarius parv. log. Liber, 1512, fol. 6r-6v), which are instituted neither by nature nor by an act of imposition, but rather are established by repetition (frequentatio) (Juan de Oria, Summul. vol. Primum, 1987, 109).