NN.Floats.Arb

Umbrella import for the Arb (ball arithmetic) oracle integration.

This is an external backend (python-flint / Arb/FLINT) called via IO.Process. It is useful for:

• rigorous enclosures of real-valued expressions (ball arithmetic),
• tight bounds for monotone nonlinearities,
• cross-checking TorchLean’s native float backends (IEEE32Exec, FP32/NF).

Trust boundary: the Python/Arb stack is an oracle. This module parses and packages its output; it does not by itself prove the Arb enclosure certificate inside Lean.