Manuscript X-G@1 · X-G.tex · section · 01566e14
The ordinary two-vertex fish
The local fish and the nonlocal product criterion › The ordinary two-vertex fish · lines 1536–1543
The derivative order two in (eq:fishambiguity) is the internal extension ambiguity. The external scalar factors may already carry derivatives. It would be incorrect to infer that every resulting local quadratic density has total derivative order at most two.