make dyad ". invertible

[tangentstorm]

I request that the dyad ". (numbers) be given an inverse. I propose the inverse be ": (as it is for monadic ".). A minor improvement would be to to use a hypen rather than an underbar for the negative sign.

I can't think of a way to make the x in x&". useful to the inverse. One idea is to make x&".^:_1 ↔ x&":, but the problem with that approach is that for most applications, x=0, yet 0&": is not a useful format (again, for most applications).

In any case, I see no reason why +:&(0&".) should fail (and its obvious substitute, +:&.". has wrong (and dangerous) semantics.

-- Dan Bron <2008-02-01T23:27:07Z>