intro v
axs : Statement → Prop
Γ : Context
e : Expr
σ : List (VR × Expr)
x : VR
h₁ : Provable axs Γ (x.type, e)
h₂ : ok axs Γ (subst_of σ)
⊢ ok axs Γ (subst_of ((x, e) :: σ))
axs : Statement → Prop
Γ : Context
e : Expr
σ : List (VR × Expr)
x : VR
h₁ : Provable axs Γ (x.type, e)
h₂ : ok axs Γ (subst_of σ)
v : VR
⊢ Provable axs Γ (v.type, subst_of ((x, e) :: σ) v)