“…In [44] (and subsequent papers) the polynomial part of the space was dropped, and then since there was no longer any "enrichment," the method was called a DG method (and abbreviated to DGM); see [44, of 1 , the method defines so-called optimal test spaces 2 N of 2 ; these optimal test spaces are such that, when the sesquilinear form satisfies the inf-sup condition (6.40), the discrete infsup condition (6.46) is automatically satisfied; see, e.g., [59,Proposition 5]. These optimal test spaces admit functions with no continuity constraints across element interfaces, hence the "discontinuous" in "DPG" [59,Definition 16], [29,Section 3]. In practice, the optimal test spaces are not computed exactly (since this would require solving BVPs on each K ∈ ) but instead are approximated [59,Section 3].…”