rename & organize some lemmas
fix NFA concatenation
pull NFA down to Set₀
DFA redefined with Fin and Subset
given Fin (m * n), determine it's "coordinate" (m, n)
proj[_*_]_ : (m : ℕ) → (n : ℕ) → Fin (m * n) → Fin m × Fin n
Dist
FinSet insertion
FinSet union
FinSet intersection
FinSet membership predicate
ε-closure
NFA concatenation
DFA redefined with Dist
FinSet membership predicate (not only BOOL!!)
DFA run & accept redefined
DFA union redefined
DFA union suspended, DFA intersection redefined
FinSet complement
DFA complement redefined
FinSet⇒List