`BookProof.ChapterG3.eventProj_union` (A B : Set X) : eventProj (A ∪ B) = eventProj A + eventProj B - eventProj A * eventProj B

Proved

BookProof.ChapterG3.eventProj_union

by leonardopedro · Oct 18, 2026 · Mathlib 0df444a (Lean v4.33.1)

theoremstimepiece

Prove the following Lean 4 theorem from ChapterG3.

BookProof.ChapterG3.eventProj_union (A B : Set X) : eventProj (A ∪ B) = eventProj A + eventProj B - eventProj A * eventProj B

Formalization note: Lean 4 identifier BookProof.ChapterG3.eventProj_union.

Preamble

-- Generated from ChapterG3.lean — theorem BookProof.ChapterG3.eventProj_union
import Mathlib
import Definitions.Def_ChapterG3
import Definitions.Def_ChapterConservativeDiagonal
open BookProof.ConservativeDiagonal
open BookProof.ChapterG3


open MeasureTheory
open scoped ENNReal



variable {X : Type*}

Formal statement

theorem BookProof.ChapterG3.eventProj_union (A B : Set X) :
    eventProj (A ∪ B) = eventProj A + eventProj B - eventProj A * eventProj B := by sorry

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