Equation Icon  ∫ ∏ ∫ ∏ ⟨𝒪 ⟩ = dχ 𝒪 (χ)e− S[χ] = d χ′𝒪 ′(χ′)e−S′[χ′], (A.1) p p p≤Λ p≤Λ −δl