intro fmla h
axs : Statement → Prop
ax : Statement
H : axs ax
⊢ ∀ (h : Formula), (h ∈ ax.ctx.hyps ∨ ∃ v, h = VR.vhyp v) → Provable axs ax.ctx (Formula.subst VR.expr h)
axs : Statement → Prop
ax : Statement
H : axs ax
fmla : Formula
h : fmla ∈ ax.ctx.hyps ∨ ∃ v, fmla = VR.vhyp v
⊢ Provable axs ax.ctx (Formula.subst VR.expr fmla)