ℎ ℎ Δ ( ) = Δ ℎ ( ) + Δ ( ) 4 2 2 ∆ = (∆ ′ℎ + [∆ ℎ ( ) + εΔ ℎ ( )] − ∆ + ∆ ℎ ) + 2 + 4 3 ℎ ∆ ℎ ( ) ⁄ = 0 = ≪ 1. Δ Δ ( ) = 0 and ( ) = 0 ∗ ∗ 3 ∗ = ℎ ′ℎ (−∆ ℎ − Δ ℎ ( ) − ∆ + ∆ ) 3 ∗ = ℎ (−∆ ′ℎ − Δ ( ) − ∆ ℎ + ∆ ) ℎ ∗ ∗ ∗ ⁄ = = ⁄ ∗ Δ ( ) = 0