| snv_bind: ∀a,I,G,L,V,T. snv h g G L V → snv h g G (L.ⓑ{I}V) T → snv h g G L (ⓑ{a,I}V.T)
| snv_appl: ∀a,G,L,V,W,W0,T,U,l. snv h g G L V → snv h g G L T →
⦃G, L⦄ ⊢ V ▪[h, g] l+1 → ⦃G, L⦄ ⊢ V •[h, g] W → ⦃G, L⦄ ⊢ W ➡* W0 →
| snv_bind: ∀a,I,G,L,V,T. snv h g G L V → snv h g G (L.ⓑ{I}V) T → snv h g G L (ⓑ{a,I}V.T)
| snv_appl: ∀a,G,L,V,W,W0,T,U,l. snv h g G L V → snv h g G L T →
⦃G, L⦄ ⊢ V ▪[h, g] l+1 → ⦃G, L⦄ ⊢ V •[h, g] W → ⦃G, L⦄ ⊢ W ➡* W0 →