lean_workbook_plus_4773

⚠️ 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 $a+b=c$ and $a^2+b^2+c^2=3$ for nonnegative numbers $a$, $b$, and $c$.

Why this node was retired

The posted statement is

theorem lean_workbook_plus_4773 (a b c : ℝ) (h₁ : a + b = c) (h₂ : a^2 + b^2 + c^2 = 3) : a + b + c = 3 ∧ a^2 + b^2 + c^2 = 3   :=  by sorry

The accepted witness refutes the answer even with source nonnegativity.

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 nonnegative a,b,c and ask for the complete solution set of a+b=c and a²+b²+c²=3; remove the invented sum=3 conclusion.

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.