excuse me if this has already been fixed.

    $ pdfinfo test1.pdf

    Creator:        ConTeXt - 2009.03.23 10:57
    Producer:       LuaTeX-0.36.0
    CreationDate:   Fri Apr 10 18:10:34 2009
    ModDate:        ConTeXt - 2009.03.23 10:57


\implies doesn't work
                               
! Undefined control sequence.
<recently read> \implies
                        
l.11 $\implies
              $
?

                                                        
*I* think \Rightarrow should be exchanged for \implies, as \implies 
generates a slightly longer arrow.

    $ pdfinfo test2.pdf

    Creator:        ConTeXt - 2009.03.23 10:57
    Producer:       pdfTeX-1.40.9
    CreationDate:   Fri Apr 10 18:11:36 2009
    ModDate:        Fri Apr 10 00:00:00 2009


%%% the file %%%

\starttext                                                                               

$\rightarrow$                                                                            

                                                                                         

$\to$                                                                                    

                                                                                         

$\leftarrow$                                                                             

                                                                                         

$\leftrightarrow$                                                                        

                                                                                         

$\implies$                                                                               

                                                                                         

$\Rightarrow$                                                                            

\stoptext  

Jesse Alama wrote:
> I switched from MkIV to MkII today because of this gap in MkIV's math:
> I need to submit a dissertation that has \rightarrow's in it.  Let's
> hope that this issue is resolved soon.
>
> Jesse
>
> Alan BRASLAU <alan.braslau@cea.fr> writes:
>
>   
>> Indeed, it seems to be broken in mkiv
>> \rightarrow
>> \to
>> \leftarrow
>> ...
>>
>> However, \leftrightarrow works.
>>
>> So, currently, it is hard to typeset limits under mkiv!
>>
>> Alan
>>
>>
>> On Tuesday 31 March 2009 09:14:16 Hans Hagen wrote:
>>     
>>> Aditya Mahajan wrote:
>>>       
>>>> On Mon, 30 Mar 2009, Jesse Alama wrote:
>>>>         
>>>>> It seems that \rightarrow is missing.  The command exists, in the sense
>>>>> that its use doesn't lead to an error, but it doesn't lead to anything
>>>>> in the output.  Minimal example:
>>>>>
>>>>> \starttext
>>>>> $\rightarrow$
>>>>> \stoptext
>>>>>           
>>>> Hans,
>>>>
>>>> What does the new arrow function in math-vfu.lua supposed to do?
>>>>         
>>> it will be used instead of the macro based one (as luatex has native
>>> support for such extenders now) but i had to wait till you fixed all the
>>> other arrows that you added someplace
>>>
>>> Hans
>>>       
>> ___________________________________________________________________________________
>> If your question is of interest to others as well, please add an entry to the Wiki!
>>
>> maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
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>> wiki     : http://contextgarden.net
>> ___________________________________________________________________________________
>>
>>     
>
>