Antisymmetry and Externalization

There are no mirror-image pairs of languages. This restriction on the otherwise vast set of possible languages must be accounted for, and puts boundary conditions on any theory of the human language faculty. There are implications for externalization and in the longer run for the evolution of the language faculty. Antisymmetric linear/temporal order is part of core syntax. Temporal order is partly (though not fully) integrated into core syntax via Merge itself. When two elements X and Y are merged, a relative linear/temporal order is assigned to them. At the same time, that instance of Merge assigns no relative order to the subparts of X and Y. Core syntax can explicitly have X precede Y without having any subpart of X precede any subpart of Y.