M
Martin Brown
Guest
On Mar 14, 11:50 am, jmfbah...@aol.com wrote:
understanding.
business and yet haven't heard of recursion.
Unhinged is wrong though - the problem is only self referential. There
is at worst a simple tail recursion that can be easily unwound. But
since you cannot cope with this very basic concept here is a concrete
example.
(*) The decimal checksum of this ASCII sentence is exactly 05407
fuBAH, Unhinged and MassivelyWrong might like to check this assertion-
the text of the sentence starts with "(" and ends with "7"
It is the sort of elegant toy puzzle that Martin Gardner would delight
in.
CRC16 would take a lot more effort.
Regards,
Martin Brown
You could so easily have done both if you had just an ounce ofIn article <1173870480.508596.143...@n76g2000hsh.googlegroups.com>,
"Martin Brown" <|||newspam...@nezumi.demon.co.uk> wrote:
On Mar 13, 10:34 am, jmfbah...@aol.com wrote:
This is the point. It will never be "correct" because the file
contains a checksummed listing of itself.
snip
Do the exercise. Then you will see what I'm talking about.
You really are determined to parade your ignorance. File checksums are
trivial to make internally consistent.
At the simplest conceptual level you could define all files to have
checksum=0 and add some fluff to the end of each one to make it so. In
this case you only need to adjust theTAPE.DIRand since you know the
effect of changing the bytes in the checksum representation on the
checksum it is relatively easy to program a self consistent solution.
then self consistent solutions can be found by SMOP.
It isn't a goal to have the checksum ofTAPE.DIRcorrect. It was
a mandatory goal to have a directory of the tape on the tape. The
tradeoff to accomplish this goal was to have the checksum of
the fileTAPE.DIRnot match the checksum ofTAPE.DIRreported
inTAPE.DIR.
understanding.
Hells bells! Clearly you cannot!!! You claim to have been in theQuery: Is the ability to think about this concept (Mr. unsettled
called itrecursion) a rare ability?
business and yet haven't heard of recursion.
Unhinged is wrong though - the problem is only self referential. There
is at worst a simple tail recursion that can be easily unwound. But
since you cannot cope with this very basic concept here is a concrete
example.
(*) The decimal checksum of this ASCII sentence is exactly 05407
fuBAH, Unhinged and MassivelyWrong might like to check this assertion-
the text of the sentence starts with "(" and ends with "7"
It is the sort of elegant toy puzzle that Martin Gardner would delight
in.
CRC16 would take a lot more effort.
Regards,
Martin Brown