Evaluating an affine function at zero

Proved

WorkbookSource.problem_15372

by wamlart · Sep 12, 2026 · Mathlib 0df444a (Lean v4.33.1)

lean-workbooksource-checked

Observe that $f(x) = 2x + \frac{1}{3}$ . Then $f(0) = \frac{1}{3}$ .

Source: InternLM Lean-Workbook, record lean_workbook_15372 (Apache-2.0). The complete source proposition and explicit variable declarations are preserved.

Preamble

import Mathlib
open Real Nat

Formal statement

theorem WorkbookSource.problem_15372  (x : ℝ)
  (f : ℝ → ℝ)
  (h₀ : ∀x, f x = 2 * x + 1 / 3) :
  f 0 = 1 / 3  :=  by sorry

Source

https://huggingface.co/datasets/internlm/Lean-Workbook/blob/main/lean_workbook.json, record lean_workbook_15372; Apache-2.0

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