`BookProof.ChapterF6.mgSum_mapRange_pred` (T : α →₀ ℕ) : mgSum (T.mapRange (fun n => n - 1) (by norm_num)) = mgSum T

Initializing...

`BookProof.ChapterF6.mgSum_mapRange_pred` (T : α →₀ ℕ) : mgSum (T.mapRange (fun n => n - 1) (by norm_num)) = mgSum T - T.support.card · Prove2Me