Example of being burned by something analogous to Use clause

[harbaughs@EGLIN-VAX.ARPA]

From: trwrb!sdcrdcf!lwall@ucbvax.berkeley.edu
Have you guys actually been burned by USE clauses, or are you just afraid of
the dark?
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Yes, I (we) were burned just the other day. The situation
was when using a spreadsheet. I know it isn't Ada but I
believe the fundamental problem is with the human brain not
the particular language. If you don't accept that premise
then you probably want to skip over the example.
The spreadsheet used the string "total G&A" in two places
once in the salary distribution as a component of total
salaries and once again as you would expect for the
total g&a to date. When reading a printout of about
2 pages (we have a small company) the reader easily
overloads the meaning of "total G&A" in the context of
it's location but when reading the screen only one usage
appears at a time due to the small 24 line window. You
have probably guessed that the wrong "total G&A" was used
in a calculation. Fortunately the resultant answer failed
a reconciliation (the accountant's term for what we
call assertions). The lesson is to use fully qualified
names whether on spreadsheets or Ada programs. Hope you
found this interesting. I find it interesting
that Government auditors insist on
an organized system of assertion checking whereas most Government
software customers do not (to my knowledge).
regards, sam harbaugh
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