The negative answer is provided by a version of Tarski’s theorem of the indefinability of truth. The weakest Tarskian metalanguage for LGTC will consist in expanding LGTC by means of concepts and a theory of the syntax of LGTC. But the mathematical part of the metalanguage will be the same, for that’s the “sufficiently developed system of mathematical logic” of which Tarski spoke. Further, the metalanguage will obviously contain its object language as part, both its grammar (under no translation) and its deductive system, because LGTC will appear both in the object language and in the metalanguage (cf. Tarski 1983b, p. 247).