# Superscript prime symbol

x\[Prime] looks like $x_'$, ugly right? Is there a way to make a symbol with prime to look like $x'$?

That's what I'm trying right now:

Notation[ x_', Primed[x_]]
Primed[x_] := Symbol[SymbolName[x] <> "\[Prime]"]


But how then I use it in patterns? If I do this:

f[q_, q':_] := q + q'


Weird syntax errors appear:

Syntax::sntxf: "T[r_," cannot be followed by "q':_]".
Syntax::tsntxi: "q':_" is incomplete; more input is needed.
Syntax::sntxi: Incomplete expression; more input is needed .


If we replace q':_ with Pattern[q',_] another error:

Pattern::patvar: "First element in pattern Pattern[q',_] is not a valid pattern name. "


But Head[q'] returns Symbol and Pattern requires a Symbol as first parameter.

What is wrong?

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Why not type x'? –  rm -rf Oct 3 '12 at 17:33
@rm-rf Because it will be a derivative then and not a symbol. –  swish Oct 3 '12 at 17:44
Ah, you want to be able to do things like $x^\prime=3$, then? –  Ｊ. Ｍ. Oct 3 '12 at 17:48
@J.M. Yes, but without Needs["Notation"];Symbolize[x']. –  swish Oct 3 '12 at 17:52
Actually I can't even symbolize a symbol with prime like this, I was sure that would work. –  swish Oct 3 '12 at 18:08

This is not really ideal, but it gets you most of the way there:

SetAttributes[makeSuperscript, HoldAllComplete];
makeSuperscript[sym_Symbol] := (
sym /: MakeBoxes[sym, form_] = With[{name = SymbolName[sym]},
InterpretationBox[SuperscriptBox[name, "\[Prime]"], sym]
];
sym
);

makeSuperscript[q]
(* -> InterpretationBox[SuperscriptBox["q", "\[Prime]"], q] *)


The symbol is still called q, but it now looks like $q'$, as the InterpretationBox is not visible. You can either copy and paste the superscripted form (to make assignments, or use in other expressions) or enter it as q, as you prefer.

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But I want to have this notation inside input, mostly in patterns, so that functions like f[x'_] := x' would work. Basically I want \[Prime] to be higher. –  swish Oct 3 '12 at 19:29
@swish after evaluating makeSuperscript[x], f[x_] := x displays in the way that you want. If you copy and paste the output of Information[f], it works as input, even in a new session. I know this is not quite how you envisioned this working, but unfortunately I'm not aware of any reasonably safe way of accomplishing that. Even if you use a different font that has a higher-up \[Prime], you'll still need a StyleBox for it to display as such unless you edit the font mapping file UnicodeFontMapping.tr. –  Oleksandr R. Oct 3 '12 at 19:48
That causes q to display as q^\[Prime]. But you could instead use InterpretationBox[SuperscriptBox[name, "\[Prime]"], Symbol[name <> "\[Prime]"]]. –  Mechanical snail Dec 6 '12 at 23:19
@Mechanicalsnail yes, that's right, but the point was to have a symbol that appeared to be primed without having to have ' or \[Prime] in its actual name due to likely confusion (of both the user and Mathematica itself) with Derivative[1]. If you really want \[Prime] in the name then yes, your suggestion is sensible. One could also use any other Unicode character that displays in approximately the right way. –  Oleksandr R. Dec 7 '12 at 7:57
@OleksandrR.: The Derivative confusion only occurs with an apostrophe, not \[Prime]. The asker wanted to be able to use unprimed and primed in the same expression. –  Mechanical snail Dec 8 '12 at 0:54

This is an unashamed variation on @Oleksandr R's post but prompted by the OP comment "Basically I want \[Prime] to be higher."

Using adjustment boxes you can position the prime exactly where you want. Easiest way to do set the position is probably to type x\[Prime] and go to the menu Insert > Typesetting and nudge the prime around.

SetAttributes[higherPrime, HoldAllComplete];

higherPrime[
sym_Symbol] := (sym /: MakeBoxes[sym, form_] =
With[{name = SymbolName[sym]},
RowBox[{name,
AdjustmentBox["\[Prime]", BoxBaselineShift -> -0.9,
BoxMargins -> {{-0.15, 0}, {0, -0}}]}]];
sym);


-
The main problem is that FullForm[higherPrime[x]] is stil x`, so it's impossible to use both primed and unprimed versions of one symbol. Nudge Up is a great suggestion, what we need now is the way to automate it. –  swish Oct 3 '12 at 21:54