problems with lookup~ around zero

Hi listmembers,

Realizing that a lookup~ table was not doing what I wanted it to do I
was trying to build a simple input = output table.

I could not get rid of the problem that if I input values little below
zero,
the lookup~ object gives me positive values instead of negative ones.
What I need is the lookup~ object beeing able to deal with negative
values
as proper as it does with positive values.

A patch to illistrate the problem is below.

I'd be glad for hints to solve this problem.

Thanks and best, Cor

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