MathGloss

An orthonormal sequence of vectors viiN{v_i}_{i\in\mathbb N} in a Hilbert space HH is an orthonormal (Hamel) basis for HH if h=iNvi,hvih = \sum_{i\in\mathbb N} \langle v_i, h\rangle v_i for all hHh \in H.

Wikidata ID: Q189569