lean_workbook_plus_18052

⚠️ Retired — specification defect

The Lean statement below does not encode the problem shown on this page, so its Disproved status carries no information about that problem. Do not import this node or use it as a dependency.

Prove that $197.99494949\ldots$ is equal to $198 - 1/198$ .

Why this node was retired

The posted statement is

theorem lean_workbook_plus_18052 (x : ℝ) (hx : x = 197.99494949) : x = 198 - 1/198   :=  by sorry

An infinite decimal was replaced by a finite truncation, and the source’s printed repetend is ambiguous.

The recorded counterexample refutes the statement as encoded. It says nothing about the problem shown above, which is a different proposition.

Proposed corrected statement

Define the intended infinite expansion by a convergent digit series. Since1/198=0.00505050…, the exact value198−1/198 is197.99494949… with the appropriate repeating49 tail, not the displayed terminating 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.