- λG,L0,T0. ❪G,L0❫ ⊢ T0 ![h,a] →
- ∀n1,T1. ❪G,L0❫ ⊢ T0 ➡*[h,n1] T1 → ∀n2,T2. ❪G,L0❫ ⊢ T0 ➡*[h,n2] T2 →
- ∀L1. ❪G,L0❫ ⊢ ➡[h,0] L1 → ∀L2. ❪G,L0❫ ⊢ ➡[h,0] L2 →
- ∃∃T. ❪G,L1❫ ⊢ T1 ➡*[h,n2-n1] T & ❪G,L2❫ ⊢ T2 ➡*[h,n1-n2] T.
+ λG,L0,T0. ❨G,L0❩ ⊢ T0 ![h,a] →
+ ∀n1,T1. ❨G,L0❩ ⊢ T0 ➡*[h,n1] T1 → ∀n2,T2. ❨G,L0❩ ⊢ T0 ➡*[h,n2] T2 →
+ ∀L1. ❨G,L0❩ ⊢ ➡[h,0] L1 → ∀L2. ❨G,L0❩ ⊢ ➡[h,0] L2 →
+ ∃∃T. ❨G,L1❩ ⊢ T1 ➡*[h,n2-n1] T & ❨G,L2❩ ⊢ T2 ➡*[h,n1-n2] T.