Prove2Me

lean_workbook_plus_60118

Proved

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

Prove the equation for the real part of the product of two complex numbers: (a+bi)(c+di)=(ac−bd)+i(ad+bc)(a + bi)(c + di) = (ac - bd) + i(ad + bc).

Preamble
import Mathlib.Analysis.Complex.Basic
Formal statement
theorem lean_workbook_plus_60118 (a b c d : ℝ) : (a + b * Complex.I) * (c + d * Complex.I) = (a * c - b * d) + (a * d + b * c) * Complex.I   :=  by sorry
Source
https://huggingface.co/datasets/internlm/Lean-Workbook

View graph