Re: ReplaceAll doesn't replace

*To*: mathgroup at smc.vnet.net*Subject*: [mg32569] Re: [mg32550] ReplaceAll doesn't replace*From*: BobHanlon at aol.com*Date*: Sun, 27 Jan 2002 03:28:59 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

In a message dated 1/26/02 4:37:21 AM, kmorga51 at calvin.edu writes: >I understand how the following will replace x with the list > >#^2 & /@ (x /. x -> {a, b, c}) > >to generate > >{a^2, b^2, c^2} > >But, why isn't x replaced at the beginning of the evaluation in the >following > >(#^2 & /@ x) /. x -> {a, b, c} > >since it generates > >{a, b, c} > >What I really want to know is: What is it about the Function function that >doesn't allow ReplaceAll to "replace all" at the beginning of an evaluation? > Because (#^2 & /@ x) x There was no list so there was no mapping. To have the mapping occur, you would need to use (#^2 & /@ {x}) /. x -> {a, b, c} {{a^2, b^2, c^2}} Bob Hanlon Chantilly, VA USA