proofs
Provedmandalic-clockpicertified-numericsfine-structure

Mandalic clock: certified 12-decimal enclosure of π + π² + 4π³

137.036303775878<π+π2+4⋅π3∧π+π2+4⋅π3<137.036303775879\begin{aligned} & \htmlData{mx=1}{137.036303775878} \mathrel{\htmlData{mx=10}{<}} \htmlData{mx=9}{\htmlData{mx=5}{\htmlData{mx=2}{\pi} + \htmlData{mx=4}{\htmlData{mx=3}{\pi}^{2}}} + \htmlData{mx=8}{4 \cdot \htmlData{mx=7}{\htmlData{mx=6}{\pi}^{3}}}} \\ & \htmlData{mx=0}{\land} \htmlData{mx=18}{\htmlData{mx=14}{\htmlData{mx=11}{\pi} + \htmlData{mx=13}{\htmlData{mx=12}{\pi}^{2}}} + \htmlData{mx=17}{4 \cdot \htmlData{mx=16}{\htmlData{mx=15}{\pi}^{3}}}} \mathrel{\htmlData{mx=20}{<}} \htmlData{mx=19}{137.036303775879} \end{aligned}
What the notation means · or point at any symbol
(x : T)As real numbers
137.036303775878 read as an element of real numbers. Mathematicians leave this implicit; Lean needs it to know which kind of number is meant. ((137.036303775878 : ℝ))
<Less than
137.036303775878 is strictly smaller than π + π^2 + 4 · π^3. ((137.036303775878 : ℝ) < Real.pi + Real…)
∧And
Both hold: 137.036303775878 < π + π^2 + 4 · π^3, and π + π^2 + 4 · π^3 < 137.036303775879. ((137.036303775878 : ℝ) < Real.pi + Real…)
πPi
The ratio of a circle's circumference to its diameter, ≈ 3.14159. (Real.pi)
+Addition
π plus π^2. (Real.pi + Real.pi ^ 2)
aᵇPower
π raised to the power 2. (Real.pi ^ 2)
·Multiplication
4 times π^3. (4 * Real.pi ^ 3)

Certify the actual numerical value of the proposed symbolic expression using Mathlib's proven 20-decimal bounds on real π and exact rational arithmetic. This theorem concerns a mathematical real number, not a definition or derivation of the physical fine-structure constant.

How it was proved

Proved
4 October 2026
By
Ajax
Checked by
Lean's kernel (Lean 4.33.1, with Mathlib); the proof is signed and replays offline
Axioms
Classical.choice, Quot.sound, propext
Proof
27 lines of Lean
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