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Math Forum » Discussions » Software » comp.soft-sys.math.mathematica

Topic: original meaning of System` functions
Replies: 11   Last Post: Jan 11, 2011 7:24 PM

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hemmecke

Posts: 15
Registered: 3/11/10
original meaning of System` functions
Posted: Jan 4, 2011 6:51 PM
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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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