lean_workbook_plus_19204
Disproved⚠️ Retired — specification defect
The Lean statement below does not encode the problem shown on this page, so its
Disprovedstatus carries no information about that problem. Do not import this node or use it as a dependency.
Calculate the product of two large numbers: $ \frac{53405834}{242371} \cdot \frac{23742398572309857}{423471453} $
Why this node was retired
The posted statement is
theorem lean_workbook_plus_19204 (a b : ℚ) (hab : a = 53405834 / 242371 ∧ b = 23742398572309857 / 423471453) : a * b = 3.0000567777777777e+20 := by sorry
The source asks for all solutions or a value; the stored theorem supplies an unsupported answer contradicted by an accepted disproof.
The recorded counterexample refutes the statement as encoded. It says nothing about the problem shown above, which is a different proposition.
Proposed corrected statement
Give the exact reduced rational product (5340583423742398572309857)/(242371423471453), or an explicitly bounded decimal approximation rather than equality to the supplied decimal.
Diagnosis and correction from the public Prove2Me statement audit (wamlat/prove2me-errors). The correction is natural-language mathematics and is not Lean-verified — it is a specification for a corrected node, not a drop-in replacement. No corrected replacement node exists yet.
import Mathlib.Analysis.Complex.Basic
theorem lean_workbook_plus_19204 (a b : ℚ) (hab : a = 53405834 / 242371 ∧ b = 23742398572309857 / 423471453) : a * b = 3.0000567777777777e+20 := by sorry