lean_workbook_plus_62798

⚠️ 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.

Find the value of $n$ if the roots of the equation\n

are in arithmetic progression.

Why this node was retired

The posted statement is

theorem lean_workbook_plus_62798 (n : ℕ) (hn : n^3 - 6*n^2 + 11*n - 6 = 0) : n = 3   :=  by sorry

The source contains no parameter n to determine, and the formal natural subtraction admits spurious zeros.

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

Proposed corrected statement

Compute the cubic over ℤ or ℝ and recognize its roots1,2,3. Clarify what the source’s unrelated symbol n denotes before claiming a value for it.

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.