[itex]0^0[/itex] (that is, if ^ is the exponentiation function, ^(0, 0)) is sometimes undefined. The only argument I've seen for this is that [itex]0^0[/itex] is an indeterminate form, though I don't accept that as an argument against defining ^(0, 0). It seems that [itex]0^0[/itex] could be interpreted as an indeterminate form or as ^(0, 0) = 1 depending on context without difficulty. On the other hand, I've found four good arguments for letting ^(0, 0) = 1: it makes the binomial theorem work out, it makes our notation for power series work out, it makes sense if m^n is the number of functions from an n-element set to an m-element set, and it follows from a natural definition of exponentiation via repeated products, using the empty product as 1. So, is there any good argument for leaving it undefined?