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Re: Replacement rules with I (sqrt(-1)

• To: mathgroup at smc.vnet.net
• Subject: [mg45061] Re: Replacement rules with I (sqrt(-1)
• From: Jean.Pellegri at wanadoo.fr (Jean Pellegri)
• Date: Mon, 15 Dec 2003 06:02:55 -0500 (EST)
• References: <brhi2e$jha$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Jean-Michel Collard <jm at france-paris.org> wrote in message news:<brhi2e$jha$1 at smc.vnet.net>...
> Can someone explain me this particular behavior :
> 
> x+I*y /. I -> -I
> 
> x-I y  (*  ok  *)
> 
> 
> 3+I /. I-> -I
> 
> 3+I     (*  ????? false  *)
> 
> Regards,
> 
> J.-M.

Une remarque : 

FullForm[x + I*y] donne Plus[x,Times[Complex[0,1],y]]

FullForm[3 + I] donne Complex[3,1] et non pas Plus[3,Times[Complex[0,1],1]]

Pet-être est la raison ?

Jean Pellegri