have s2 : reachable_from_list g stack ⊆ (dft_aux g stack []).toFinset.toSet := reachable_from_list_closed_dft_aux g stack
Node : Type
inst✝ : DecidableEq Node
g : Graph Node
stack : List Node
s1 : ↑(dft_aux g stack []).toFinset ⊆ reachable_from_list g stack
⊢ ↑(dft_aux g stack []).toFinset = reachable_from_list g stack
Node : Type
inst✝ : DecidableEq Node
g : Graph Node
stack : List Node
s1 : ↑(dft_aux g stack []).toFinset ⊆ reachable_from_list g stack
s2 : reachable_from_list g stack ⊆ ↑(dft_aux g stack []).toFinset
⊢ ↑(dft_aux g stack []).toFinset = reachable_from_list g stack