“…where Z � = (Σ) and Σ � = (Z) play the same roles for the inverse homeomorphism −1 ∶ D � → D as Z and Σ do for ; for the details, see [, Section 1]. 7 Moreover, if ∶ D → D � belongs to W 1 1,loc (D) or ∈ ACL(D) , then [7, Section 1] shows that Hence, for Sobolev-class mappings, we may assume from the outset that…”