The axiom of constructibility, written $V=L$, is the assertion that the universe of all sets is exactly the [[Constructible universe]]. It is minimalistic in the sense that any inner model $M$ of ZF must contain all sets from Gödel's constructible universe $L$. The axiom is compatible with some of the smaller large cardinal notions such as weak compactness but is *not* compatible with any large cardinal notion implying the existence of $0^{\sharp}$ ([[Zero sharp]]) such as measurability.