Re: Count[{Unevaluated[a]},Unevaluated[a]]

*To*: mathgroup at yoda.physics.unc.edu*Subject*: Re: Count[{Unevaluated[a]},Unevaluated[a]]*From*: John Lee <lee at math.washington.edu>*Date*: Wed, 2 Dec 92 10:32:47 -0800

> the above gives - a little bit surprisingly for me - 0. > With a third argument: Count[{Unevaluated[a]},Unevaluated[a],{-1}] > the result is 1 (as expected). Using On[] one sees that > Count "evaluates" its arguments. Literal instead of Unevaluated gives > a similar result. > Why does Count do this? Try Count[Unevaluated[{a}],Unevaluated[a]]. In your form, {Unevaluated[a]} passes a unevaluated to List, which results in [a], which is then passed to Count. Jack Lee Dept. of Mathematics University of Washington Seattle, WA