# Prime number determinatorer!

Number Theory Level pending

Suppose the mod function is defined as $$\text{mod}(x,y) = x- y \left\lfloor \dfrac{x}{y} \right\rfloor$$. Then define $$\large f(x) = \text{mod}((x-(\text{mod}((x-1)!,x)),x)$$ for all positive integers $$x$$. Then $$f(x)$$ is a function which returns 1 if $$x$$ is prime, 0 if not.

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