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original meaning of System` functions

  • To: mathgroup at smc.vnet.net
  • Subject: [mg115240] original meaning of System` functions
  • From: hemmecke <hemmecke at gmail.com>
  • Date: Tue, 4 Jan 2011 18:51:42 -0500 (EST)

Is there any way to call the original Mathematica behaviour of a
function from the System context in case it has previously been
unprotected and redefined?

For example, how can I access the original meaning of ClearAll after

Unprotect[ClearAll,Clear]; ClearAll[__]:=True;Clear[__]:=True;

?

I just temporarily (i.e. in some safe environment) want to access the
system defined meaning, but actually don't want to undo any modified
behaviour.

Ralf

In[1]:= Unprotect[ClearAll,Clear]; ClearAll[__]:=True;Clear[__]:=True;

In[2]:= SetAttributes[ClearAll,{Protected, Locked}]

In[3]:= SetAttributes[Clear,{Protected, Locked}]

In[4]:= a[x_]:=x^3

In[5]:= ClearAll[a]

Out[5]= True

In[6]:= ClearAll[ClearAll]

Out[6]= True

In[7]:= System`ClearAll[a]

Out[7]= True

In[8]:= ??a
Global`a

a[x_] := x^3


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