Prove2Me

lean_workbook_plus_3309

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

Suppose that 4a=54^a=5 , 5b=65^b=6 , 6c=76^c=7 , and 7d=87^d=8 . What is a⋅b⋅c⋅da\cdot b\cdot c\cdot d ?

Preamble
import Mathlib.Analysis.Complex.Basic
Formal statement
theorem lean_workbook_plus_3309 (a b c d : ℝ) (h1 : (4:ℝ)^a = 5) (h2 : (5:ℝ)^b = 6) (h3 : (6:ℝ)^c = 7) (h4 : (7:ℝ)^d = 8) : a*b*c*d = 3/2   :=  by sorry
Source
https://huggingface.co/datasets/internlm/Lean-Workbook

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