In [KwoM] it is proved that the the core model K exists under the assumption that there is no inner model having a Woodin cardinal and satisfying ZFC. Furthermore, they also mention that the result is the "best possible", in the sense that we cannot weaken this anti-large-cardinal hypothesis without strengthening the remainder of the hypothesis. From what I understand, using the core model induction (which I must admit I don't know the details of yet), K can be constructed below any finite number of Woodin cardinals. So my question is then whether or not K has been constructed below $\omega$ many Woodins and if so, what the extra hypothesis is? If this is indeed the case, I would greatly appreciate a reference to the given paper. *[KwoM] Jensen and Steel: "K without the measurable"* **Edit:** In the introduction to [Schindler and Steel's "The Core Model Induction"][1], they write that if we assume that there is no proper class model with $n+1$ Woodins and over every set there is a proper class model with $n$ Woodins, then $K$ exists (in the sense of the above [KwoM]). Can this be extended to: if there is no proper class model with $\omega$ Woodins and over every set there is a proper class model with $n$ Woodins, for every $n<\omega$, then $K$ exists? [1]: http://wwwmath.uni-muenster.de/logik/Personen/rds/core_model_induction.pdf