lean_workbook_plus_14424

⚠️ 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 the system of equations: $x^2 - y = 4$ and $y = x + 1$

Why this node was retired

The posted statement is

theorem lean_workbook_plus_14424 (x y : ℝ) (h₁ : x^2 - y = 4) (h₂ : y = x + 1) : x = 1 ∨ x = 2   :=  by sorry

The inserted roots1 and2 are wrong.

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

Proposed corrected statement

Classify the solutions as x=(1±√21)/2 and y=x+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.