# [racket] arity of + versus <=

On Fri, Oct 28, 2011 at 11:08 AM, Carl Eastlund <cce at ccs.neu.edu> wrote:
>*
*>* You seem to be assuming that we have to pick one binary->nary for all
*>* binary operators.
*
That is the nature of `generalization'. If I have to discriminate, it isn't
general.
>* I would choose this one for relations and the other
*>* one for associative operators with identities.
*
And you thus answer the original poster's question.
`` is there a rationale beyond historical precedent
for + and * to allow any number of arguments but, =, <=, <, >, >= to
require at least two arguments?''
Yes. The two generalizations are different.
I made a clumsy argument to this effect by showing that the natural
generalization
for add and multiply do not extend to relational operators.
--
~jrm