On Mon, Jun 27, 2022 at 5:58 PM Elijah Stone <elro...@elronnd.net> wrote: > > as I understand it, this left-right arrow is used in math to symbolize "if > > and only if" > > The iff arrow uses two bars, cf ⟺ . > > > > ... But, here, it's worth noting that math relies heavily on contextual > > constraints, and that we routinely and explicitly ignore concepts which > > would conflict with those surrounding constraints. > > Yes. And in apl context, the symbol ↔ means 'can be substituted for' or 'is > equivalent to'.
Ok, thanks. That said, I would consider "rank" as being analogous to "domain", and the use of left right arrow in (for example) an integer domain does not mean that the equivalence holds in a complex domain (let alone a vector domain). Anyways, thanks for the clarification, -- Raul ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm