lean_workbook_plus_51617

⚠️ 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.

$a \le \frac {15}{2} , b = \frac {30 - a}{3} , c = \frac {30 - a}{3}$

Why this node was retired

The posted statement is

theorem lean_workbook_plus_51617 (a b c : ℝ) (h₁ : a ≤ 15 / 2) (h₂ : b = (30 - a) / 3) (h₃ : c = (30 - a) / 3) : a + b + c = 30   :=  by sorry

The source gives no sum-30 conclusion; the target invents one inconsistent with the prescribed b,c.

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

Proposed corrected statement

From the stated b=c=(30−a)/3 derive a+b+c=20+a/3. Recover the original optimization context if a different sum was intended.

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.