In the
foundations of mathematics, a
covering lemma is used to prove that the non-existence of certain
large cardinals leads to the existence of a canonical
inner model, called the
core model, that is, in a sense, maximal and approximates the structure of the
von Neumann universe V. A
covering lemma asserts that under some particular anti-large cardinal assumption, the core model exists and is maximal in a sense that depends on the chosen large cardinal.