lean_workbook_plus_1994

⚠️ 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.

Evaluate $\lim_{x \rightarrow 1} f(x)$ using the Squeeze Theorem with $3x \leq f(x) \leq x^3+2$ for $0 \leq x \leq 2$.

Why this node was retired

The posted statement is

theorem lean_workbook_plus_1994 (f : ℝ → ℝ) (hf: ∀ x:ℝ, 0<= x ∧ x <=2 → 3*x <= f x ∧ f x <= x^3+2): ∀ x:ℝ, 0<= x ∧ x <=2 → 3 <= f x ∧ f x <= 3   :=  by sorry

A squeeze-theorem limit at1 became pointwise equality to3 throughout[0,2].

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

Proposed corrected statement

Under the given bounds on[0,2], prove lim_(x→1)f(x)=3 using the two continuous bounding functions; only f(1)=3 follows as a pointwise value.

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.