Re: Parenthesis reduction
- To: mathgroup at smc.vnet.net
- Subject: [mg126956] Re: Parenthesis reduction
- From: John Doty <noqsiaerospace at gmail.com>
- Date: Wed, 20 Jun 2012 03:50:18 -0400 (EDT)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <jrlfoa$c2s$1@smc.vnet.net> <jrmthi$h6o$1@smc.vnet.net> <jrp8sq$q97$1@smc.vnet.net>
On Tuesday, June 19, 2012 3:14:34 AM UTC-4, Nasser M. Abbasi wrote:
using V 8.04, this does nothing?
>
> In[1]:= Sequence@@{{a,b,c},{d,e,f},{g,h,i}}
> Out[1]= Sequence[{a,b,c},{d,e,f},{g,h,i}]
What did you expect it to do? {a,b,c},{d,e,f},{g,h,i} is not a proper expression: it has no head, so Sequence[] cannot return it. Sequence[] is not really comprehensible as a "function": in effect it edits its caller's argument list!
Try f[Sequence@@{{a,b,c},{d,e,f},{g,h,i}}]
Always remember that fundamentally, Mathematica is *rewriting expressions* according to rules that *often* correspond to procedure or function evaluation, but sometimes are really something else.