# Fractals The 2 definitions of the fractals library, each with its Epsil spelling, its MathJSON name, its signature and its full description. Each definition is listed under its Epsil spelling (the MathJSON name when it has none), with its signature in the engine's type syntax. The [Standard Library](/library/) page is the one-page index of every category. ## Definitions ### julia MathJSON `Julia` · `(complex, complex, integer) -> real` Smooth escape-time value for a Julia set with parameter c. Returns 1 for points inside the set, values in [0,1) for escaping points. ### mandelbrot MathJSON `Mandelbrot` · `(complex, integer) -> real` Smooth escape-time value for the Mandelbrot set. Returns 1 for points inside the set, values in [0,1) for escaping points.