It is constrained by laws and regulations formulated by Congress over more than two centuries.
( It ( ( is ( constrained ( by ( ( ( laws and ) regulations ) ( formulated ( by ( Congress ( over ( ( more ( than two ) ) centuries ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ is) (VP (VBN constrained) (PP (IN by) (NP (NP (NNS laws) (CC and) (NNS regulations)) (VP (VBN formulated) (PP (IN by) (NP (NP (NNP Congress)) (PP (IN over) (NP (QP (JJR more) (IN than) (CD two)) (NNS centuries)))))))))) (. .)))
There are no laws constraining it.
( There ( ( are ( ( no laws ) ( constraining it ) ) ) . ) )
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (NP (DT no) (NNS laws)) (VP (VBG constraining) (NP (PRP it))))) (. .)))