Rule to Function, Frontend funnies

• To: mathgroup at smc.vnet.net
• Subject: [mg5307] Rule to Function, Frontend funnies
• From: Wouter Meeussen <meeussen.vdmcc at vandemoortele.be>
• Date: Sat, 23 Nov 1996 01:44:44 -0500
• Sender: owner-wri-mathgroup at wolfram.com

```how can I convert a rule to a function?
if I get a result from

rulesoln = DSolve[{y'[x]==y[x]/(c+1/x),y[0]==1},y[x],x]

in the form :

2
x/c - Log[1 + c x]/c
{{y[x] -> E                     }}

how do I get the definition :

y[x_]:= E^(x/c - Log[1 + c x]/c^2)

(*************************************************************************)
Funny  : in any text editor, like notepad , I just cut & paste the pieces I
need.
In the Frontend, I can force Mma to produce a one-dimensional output line by
% // InputForm

{{y[x] -> E^(x/c - Log[1 + c*x]/c^2)}}

but when I try to edit it, or make an input-line out of that, either by
Action-Prepare.Input-Copy.Output.from.Above (Control-Shift-L)

No Input Form was generated for this Cell

(*************************************************************************)
Even Funnier : doing Control-Shift-L and Shift-Enter produces:

General::spell: Possible spelling error: new symbol name "Form"
is similar to existing symbols {CForm, For}.
General::spell1: Possible spelling error: new symbol name "for"
is similar to existing symbol "For".

Cell for Form generated Input No this was
(*************************************************************************)

Anybody out there to whom this happens too?
After some {soul,FullForm}-searching, I came up with this rule-eating-rule :

Flatten[rulesoln]/.y[x]->y[x_]/.Rule->SetDelayed

{Null}

you don't get to see much except "{Null}", but it results in:

?y

Global`y
y[x_] := E^(x/c - Log[1 + c*x]/c^2)

(*************************************************************************)

Is there a fast & easy Cut-and-Paste way to do it, not leaving the FrontEnd?
Is this the same on a Mac-machine?
Is this the same in Mma 3.0 for Windows?

Wouter.

NV Vandemoortele Coordination Center
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Prins Albertlaan 79
Postbus 40
B-8870 Izegem
Tel: +/32/51/33 21 11
Fax:+32/51/33 21 75
vdmcc at vandemoortele.be

```

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