Lines of Identity (LoI) are important elements in Existential Graphs. They can be assembled to whole networks called “ligatures.” They are not straightforwardly understandable: for example, in constrast to LoI, ligatures may stand for more than one object.
This article elaborates the handling of ligatures. It is precisely investigated how ligatures are dealt with in the calculus and how they can be modified without changing the meaning of a graph. Finally, a sufficient criterion for reading a ligature similar to a LoI is provided, as well as an algorithm which grasps the correct meaning of an existential graph even if it contains arbitrarily complex ligatures.
The official journal of the International Association for Semiotic Studies, founded in 1969 as one of the first scholarly journals in the field, Semiotica features articles reporting results of research in all branches of semiotic studies, in-depth reviews of selected current literature in the field, and occasional guest editorials and reports. The journal also publishes occasional Special Issues devoted to topics of particular interest.