Adjective
metamathematical (comparative more metamathematical, superlative most metamathematical)
Pertaining to metamathematics, a branch of mathematics dealing with mathematical systems and their nature.
Hilbert was initially a deductivist, but, as may be clear from above, he considered certain metamathematical methods to yield intrinsically meaningful results and was a realist with respect to the finitary arithmetic. Source: Internet
"Some metamathematical results on completeness and consistency," 595–96. Source: Internet