Re: DifferenitalD vs CapitalDifferenitalD
- To: mathgroup at smc.vnet.net
- Subject: [mg87938] Re: DifferenitalD vs CapitalDifferenitalD
- From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
- Date: Mon, 21 Apr 2008 03:22:28 -0400 (EDT)
- Organization: The Open University, Milton Keynes, UK
- References: <fuees1$bds$1@smc.vnet.net>
fizzy wrote: > After applying Jens correction, I was hoping to be able to use the = > DifferentialD with x, etc. and then use the 'dx' , where 'd' here is = > DifferentialD (just dont know how to add it here in the email), so it = > would be a Symbol....but this didnt work....I realize I can use the = > straight forward dx , etc. symbol but I want to highlight the = > Differential....any way to 'fix' this?....when I type in DifferentialD = > , from the Palette, and then add x to it and perform //Head on it , it = > just returns DifferentialD <snip> Hi Jerry, The behavior you have noticed is perfectly normal since the built-in function *DifferentialD[]*, which can also be entered as |esc|dd|esc| (i.e. the escape key followed by the character lowercase d twice followed by the escape key again), is a *compound operator with built-in meaning*. The full form of a complete expression with *DifferentialD[]* is DifferentialD[some_expression] (one argument is required). For instance, say we enter the expression |esc|dd|esc|z Its full form is FullForm[|esc|dd|esc|z] === DifferentialD[z] And its head is Head[|esc|dd|esc|z] === DifferentialD Thus, one cannot manipulate double struck lowercase d independently. Now, if you are interested by the above character without built-in meaning, you can get it with the following sequence of keys: |esc|dsd|dsd| Note that dsd stands for double struck lowercase d. Similarly, you can get a double struck capital C by entering |esc|dsC|esc| Finally, enter and evaluate the following sequences of keystrokes: |esc|int|esc|z |esc|dsd|esc|z |esc|int|esc|z |esc|dd|esc|z They look the same. However, the first expression generates an error message, while the second returns the expected definite integral. Regards, -- Jean-Marc