Equation Icon  ( − 1 if ℓ ∈ {i,j,k} and m ∕∈ {i,j,k}, { (αijk|α ℓm ) = ( 0 if { ℓ,m } ⊂ {i,j,k} or { ℓ,m } ∩ {i,j,k} = ∅, (10.12 ) 1 if ℓ ∕∈ {i,j,k} and m ∈ {i,j,k},