Structural linguistic theory now needs procedures for constructing systems of a higher level out of the discrete and homogeneous systems that are derived from description and that represent each a unique formal organization of the substance of expression and content. Let us dub these constructions "diasystems", with the proviso that people allergic to such coinages might safely speak of supersystems or simply of systems of a higher level. A "diasystem" can be constructed by the linguistic analyst out of any two systems which have partial similarities (it is these similarities which make it something different from the mere sum of two systems). But this does not mean that it is always a scientist’s construction only: a "diasystem" is experienced in a very real way by bilingual (including "bidialectal") speakers and corresponds to what students of language contact have called "merged system". [Weinreich, U., 1967, Languages in Contact. Findings and Problems, Columbia University, Mouton & Co., pp. 8f].
- Weinreich (1954), a pag.389-390