On Oct 28, 2011, at 8:12 AM, Joe Marshall wrote: > On Wed, Oct 26, 2011 at 8:32 PM, Dan Grossman <d...@cs.washington.edu> wrote: >> Very minor point, but is there a rationale beyond historical precedent >> for + and * to allow any number of arguments but, =, <=, <, >, >= to >> require at least two arguments? > > 0 is the additive identity. 1 is the multiplicative identity. > What is the equality identity?
No, I don't buy that. operators in \alpha X \alpha -> \beta can never have identities, but that doesn't mean they can't be generalized. I can definitely imagine that you would choose to disallow unary use of comparison operations to prevent a certain class of programming errors, but it seems pretty clear to me that the generalization of, e.g., <= is "is every sequential pair of items in the argument list related by the given operator." Am I missing something here? John
smime.p7s
Description: S/MIME cryptographic signature
_________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
