Re: BadAlgebra
- To: mathgroup at smc.vnet.net
- Subject: [mg20605] Re: [mg20557] BadAlgebra
- From: William Fairchild <fairchiw at union.edu>
- Date: Tue, 2 Nov 1999 02:35:36 -0500
- Sender: owner-wri-mathgroup at wolfram.com
It turns out that there are examples of "bad algebra" that are not removed
by Evaluate[ ], Trace[ ], etc. Here's an example using FormBox[ ]
(actually a minor modification of the mg20557 example of bad algebra):
CellPrint[Cell[BoxData[RowBox[
{"2",
FormBox[RowBox[{RowBox[{"(", "3", ")"}], "+", "1"}],
"StandardForm"]}
]], "Input"]]
Entering the above code constructs an input cell as follows:
In[n]:= 2(3)+1
which evaluates to:
Out[n]= 8
This behavior has been observed on both Windows and Mac versions of
Mathematica 4.0.1.0. The aberrant expression can be built using ordinary
typing and editing in a notebook; the CellPrint[ ] version given here is
not necessary, but serves to illustrate the key list, namely
{"2", FormBox[RowBox[{RowBox[{"(", "3", ")"}], "+", "1"}], "StandardForm"]}
which Mathematica fails to transform before handing to the kernel.
Bill Fairchild <fairchiw at union.edu>
Math. Dept.
Union College,
Schenectady, NY
518-388-6164