This book is a direct continuation of (Kornai, 2019), but unlike its predecessor, it is no

longer a textbook. The earlier volume, henceforth abbreviated S19, mostly covered material

that is well known in the field, whereas the current volume is a research monograph,

dominated by the author's own research centering on the 4lang system.

S19 attempted to cater to students of four disciplines, linguistics; computer science;

cognitive science; and philosophy. As Hinrich Sch