apply Exists.intro i
case mp.choice
Ss : List Stmt
s t : State
i : ℕ
hless : i < List.length Ss
hbody : (Ss[i], s) ⟹ t
⊢ ∃ i hless, (Ss[i], s) ⟹ t
case mp.choice
Ss : List Stmt
s t : State
i : ℕ
hless : i < List.length Ss
hbody : (Ss[i], s) ⟹ t
⊢ ∃ hless, (Ss[i], s) ⟹ t