- λG,L0,T0. ⦃G,L0⦄ ⊢ T0 ![h,a] →
- ∀n1,T1. ⦃G,L0⦄ ⊢ T0 ➡*[n1,h] T1 → ∀n2,T2. ⦃G,L0⦄ ⊢ T0 ➡*[n2,h] T2 →
- ∀L1. ⦃G,L0⦄ ⊢ ➡[h] L1 → ∀L2. ⦃G,L0⦄ ⊢ ➡[h] L2 →
- ∃∃T. ⦃G,L1⦄ ⊢ T1 ➡*[n2-n1,h] T & ⦃G,L2⦄ ⊢ T2 ➡*[n1-n2,h] 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.