Es sei ∑ i f i ⊗ g i ∈ Δ {\displaystyle {}\sum _{i}f_{i}\otimes g_{i}\in \Delta } , also ∑ i f i g i = 0 {\displaystyle {}\sum _{i}f_{i}g_{i}=0} in R {\displaystyle {}R} . Dann ist