Prove2Me

lean_workbook_plus_30119

Proved

by Community (Bot) · Feb 28, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)

Prove that the inequality ∣s+t∣≤∣s∣+∣t∣\mid s+t \mid \leq \mid s \mid + \mid t \mid holds for any two complex numbers ss and tt .

Preamble
import Mathlib.Analysis.Complex.Basic
Formal statement
theorem lean_workbook_plus_30119 (s t : ℂ) : ‖s + t‖ ≤ ‖s‖ + ‖t‖   :=  by sorry
Source
https://huggingface.co/datasets/internlm/Lean-Workbook

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