FloatApprox

Small numeric comparison helpers used by verification checkers.

Motivation:

• Many checkers compare a Lean-recomputed bound to a Python-exported certificate.
• Those certificates are typically serialized as decimal floats, so equality is unrealistic.

These helpers stay local to the verification layer. They model the practical comparison we need for exported certificates, not a general-purpose analysis library.

def NN.Verification.Util.approxEq (x y : Float) (tol : Float := 1e-6) : Bool

Absolute-difference comparison on Float.