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Oh Where, Oh Where Have My Values Gone?

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  • Subject: [mg30905] Oh Where, Oh Where Have My Values Gone?
  • From: jeffmg at (JeffMG)
  • Date: Sun, 23 Sep 2001 02:16:54 -0400 (EDT)
  • Sender: owner-wri-mathgroup at

My appologies if this has been discussed before, but a search in the MathGroup
archives didn't turn up anything that seemed to match my question.  I'm trying
to get access to the values defined for expressions having non-symbolic heads.

For typical function definitions, one has something like

In[1]:=		f[a]=1

Out[1]=		1


In[2]:=		f[b]:=2

I can see these values with the information escape.

In[3]:=		?f


			f[a] = 1

			f[b] := 2

And they appear as the downvalues for f.

In[4]:=		DownValues[f]

Out[4]=		{HoldPattern[f[a]]:>1,HoldPattern[f[b]]:>2}

However, consider the following assignments to expressions with non-symbolic

In[5]:=		f[c][d]=3

Out[5]=		3

Out[6]=		4

Out[7]=		5

According to Section A.5.3 of the Mathematica book, these are among the
DownValues for the symbol f.  I can still access them with the information

In[8]:=		?f


			f[c][d] = 3

			f[c][e] = 4

			f[d][c] = 5

			f[a] = 1

			f[b] := 2

However, when I check the downvalues for f, here's what I get:

In[9]:=		DownValues[f]

Out[9]=		{HoldPattern[f[a]]:>1,HoldPattern[f[b]]:>2}

What happened to the the other three assigments?  Aren't they also supposed to
be among the downvalues for f?  Is there any way to access them?  Any help on
this would be greatly appreciated!

Jeff Gilbert

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