lean_workbook_plus_79436

⚠️ 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.

Princess Annie’s father, King Halbert, fell ill to a very serious illness called the Blue Death. He had a rising fever, and his body is slowly turning blue starting with his feet up to his head. The royal physician went to the palace to try and cure him. However, he needed to know the temperature of the king in Celsius first, and the thermometer he brought was in Fahrenheit. He found out that the king’s temperature was $999$ degrees Fahrenheit. What was the king’s temperature in Celsius?

Why this node was retired

The posted statement is

theorem lean_workbook_plus_79436 (f c : ℝ) (h₁ : f = 999) (h₂ : c = (f - 32) / 1.8) : c = 372.7777777777778   :=  by sorry

Replace the invented Celsius value by4835/9, or a rounded decimal with an explicit error tolerance.

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

Proposed corrected statement

Replace the invented Celsius value by4835/9, or a rounded decimal with an explicit error tolerance.

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.