lean_workbook_plus_40820

⚠️ 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.

Solve this equation system\n $\{ \begin{array}{l} x^3 + y^3 = 2 \ 8x + xy + y = 2 \end{array}$

Why this node was retired

The posted statement is

theorem lean_workbook_plus_40820 (x y : ℝ) (hx : x^3 + y^3 = 2) (hy : 8*x + x*y + y = 2) : x = 1 ∧ y = -1   :=  by sorry

The accepted argument establishes existence but does not supply a verified complete replacement solution set.

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

Proposed corrected statement

Restore the source task “find all real solutions” of x³+y³=2 and8x+xy+y=2; remove the false proposed pair(1,−1).

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.