Services & Resources / Wolfram Forums / MathGroup Archive

MathGroup Archive 2010

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: More /.{I->-1} craziness

  • To: mathgroup at
  • Subject: [mg106235] Re: More /.{I->-1} craziness
  • From: Vince Virgilio <blueschi at>
  • Date: Wed, 6 Jan 2010 05:56:50 -0500 (EST)
  • References: <> <hhhmn8$o9t$>

On Jan 5, 1:43 am, Richard Fateman <fate... at> wrote:


> Are you describing Mathematica here?   It seems to me that it is an
> exception that Head[a+b*I] is Plus, but Head[3+4I] is Complex.


Please explain why that is an exception.

'a' and 'b' can be anything, not necessarily numbers. Hence a + b*I
can be anything as well (say, notebookA + notebookB * I). Not so for
3, 4, and 3 + 4*I.

Vince Virgilio

  • Prev by Date: Re: Combining data from indexed lists efficiently
  • Next by Date: Re: Re: Re: algebraic numbers
  • Previous by thread: Re: More /.{I->-1} craziness
  • Next by thread: Re: Re: More /.{I->-1} craziness