It's not really a meaningful page, because "lowest level" is ill-defined.
Usually, it means "most similar to what the hardware does" so C is lower than Python (because C makes you worry about manual memory management and gives you access to raw pointers) and assembly is lower than C (because it's a human-readable translation of machine code) and microcode is lower than assembly on processors which have it (because microcode is used to implement machine code).
However, this is mathematical code. It's all abstract. Nothing requires or takes advantage of being closer to or further from the hardware. So I guess lowest-level might mean "least like mathematical notation" or "requiring the most concepts to be defined in order to implement the mathematical notation" but that's a very odd definition. And if they meant that, why not use a language like Maxima or Octave which is designed for mathematical work, just for comparison?
