Another important operation related to tensor derivatives in continuum mechanics is integration by parts. The formula for integration by parts can be written as ∫ ∫ Ω Ω F ⊗ ⊗ ∇ ∇ G d Ω Ω = ∫ ∫ Γ Γ n ⊗ ⊗ ( F ⊗ ⊗ G ) d Γ Γ − − ∫ ∫ Ω Ω G ⊗ ⊗ ∇ ∇ F d Ω Ω