IndisputableMonolith.Numerics.Interval.PiBounds
This module supplies verified rational-endpoint intervals containing π to six decimal places of precision. Numerics work in the Recognition framework cites it when constructing bounds for trigonometric functions downstream. The module imports the Basic interval arithmetic layer and Mathlib's pi bounds to define the intervals and prove containment.
claimAn interval $I$ with rational endpoints $a < b$ such that $\pi \in I$ and $b - a < 10^{-6}$.
background
The upstream Basic module supplies verified interval arithmetic that uses rational endpoints to bound real values. This PiBounds module specializes those tools to π. The local setting is the numerics layer of Recognition Science, where exact bounds on constants support later interval computations for physical constants and functions.
proof idea
This is a definition module that constructs specific intervals (piInterval, fourPiInterval, piSqInterval) and proves containment using the imported pi bounds from Mathlib together with interval operations from Basic.
why it matters in Recognition Science
The module feeds the trigonometric interval computations in IndisputableMonolith.Numerics.Interval.Trig, which relies on these π bounds for arctan and tan intervals. It supports the constructive proofs in the Recognition framework's numerics layer.
scope and limits
- Does not extend to arbitrary precision or other irrationals.
- Does not include floating-point error analysis.
- Does not compute bounds for e or other constants.
used by (1)
depends on (1)
declarations in this module (25)
-
def
piInterval -
theorem
pi_in_piInterval -
def
piIntervalWide -
theorem
pi_in_piIntervalWide -
theorem
four_pi_gt -
theorem
four_pi_lt -
def
fourPiInterval -
theorem
four_pi_in_interval -
theorem
pi_sq_gt -
theorem
pi_sq_lt -
def
piSqInterval -
theorem
pi_sq_in_interval -
theorem
pi_pow5_eq -
theorem
pi_pow5_gt -
theorem
pi_pow5_lt -
def
piPow5Interval -
theorem
pi_pow5_in_interval -
theorem
four_pi_gt_d6 -
theorem
four_pi_lt_d6 -
def
fourPiIntervalTight -
theorem
four_pi_in_interval_tight -
theorem
pi_pow5_gt_d6 -
theorem
pi_pow5_lt_d6 -
def
piPow5IntervalTight -
theorem
pi_pow5_in_interval_tight