Re: What is f[1]? Advanced question

*To*: mathgroup at smc.vnet.net*Subject*: [mg131317] Re: What is f[1]? Advanced question*From*: amannucci <Anthony.J.Mannucci at jpl.nasa.gov>*Date*: Thu, 27 Jun 2013 06:33:15 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-outx@smc.vnet.net*Delivered-to*: mathgroup-newsendx@smc.vnet.net*References*: <20130626011408.DC7E86A2B@smc.vnet.net> <kqdshl$n34$1@smc.vnet.net>

Thanks. This is very helpful. I remain puzzled by this: u // FullForm FullForm[Symbol["u"]] FullForm[Unevaluated[Symbol["u"]] Head[u] FullForm[{1, 2, 3}] Head[{1, 2, 3}] In other words, Head and FullForm seem consist for the list, and inconsistent for the variable u. u's full form is just, literally "u", not Symbol["u"]. But the list's FullForm starts with "List". Head of Symbol["u"] is not Symbol, but "u". What gives?

**References**:**What is f[1]? Advanced question***From:*amannucci <Anthony.J.Mannucci@jpl.nasa.gov>