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Re: boundary conditions

• To: mathgroup at smc.vnet.net
• Subject: [mg121572] Re: boundary conditions
• From: "Oleksandr Rasputinov" <oleksandr_rasputinov at hmamail.com>
• Date: Tue, 20 Sep 2011 06:09:51 -0400 (EDT)
• Delivered-to: l-mathgroup@mail-archive0.wolfram.com
• References: <j54nme$91f$1@smc.vnet.net> <j5780j$ja9$1@smc.vnet.net>

On Mon, 19 Sep 2011 12:11:15 +0100, Peter Pein <petsie at dordos.net> wrote:

> Am 18.09.2011 14:20, schrieb goli:
>> what is the difference between these boundary conditions? do they
>> represent the same thing?
>> Derivative[0,1]v[t,0]==0
>> v(0,1)[t,0]==0
>>
>
> Hi,
>
> you did not try to enter the two lines above, did you?
>
> The first one would make sense if it would read
>
> Derivative[0,1][v][t,0]==0
>
> I guess you know about the meaning, because you're asking for BCs.
>
> But I can't imagine how
>
> v(0,1)[t,0]==0
>
> should make sense without an extension of Mathematica's parser.
>
>
> Peter
>

Apart from the fact that neither of these has been typed in correctly, if  
one interpolates the likely meaning, then yes, they represent the same  
thing: the first is in InputForm (or FullForm) while the second is in  
StandardForm. The underlying expressions are identical.