#2552 No description of the Function:derivative

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open
nobody
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5
2013-02-21
2013-02-21
Valery Lovchikov
No

Function part(expr,0) is the same as op(expr) .
Here is what is written in the Help:


Returns the main operator of the expression expr ( op )

Returns parts of the displayed form of expr ( part(expr,0) )

inpart(expr,0) return the internal representation of the expression


Executing of

op(diff(x(q),q))

and

inpart(diff(x(q),q))

gives the same result:

derivative

But ANY formal description of Function:derivative(...) is missing in the Help.
I think it is more logical to get diff in the first case, but not derivative

Executing of

derivative(x(q),q)

gives the same result as:
diff(x(q),q)

But again, the Help has no description of the Fucntion:derivative.

Discussion