https://w3id.org/framester/conceptnet5/data/en/banach_space <https://w3id.org/framester/conceptnet5/schema/IsA> <https://w3id.org/framester/conceptnet5/data/en/vector_space.n> <https://w3id.org/framester/conceptnet5/schema/RelatedTo> <https://w3id.org/framester/conceptnet5/data/en/hilbert_space> risorse dalla linked data cloud