## Question

Everything about Sudoku that doesn't fit in one of the other sections
ronk wrote:
gsf wrote:first, the proposition constraint P(FN) is not considered guessing in this context
(...)
about using backdoors, its a fallout from the definition of the P (proposition) constraint
each proposition can have 3 outcomes: contradiction, solution, inconclusive

In this context the primary purpose of the proposition is to find a contradiction. If a secondary purpose of the proposition is to solve the puzzle, then it is guessing IMO.

I remember discussions related to this a while back and didn't understand how
collateral information gathered by a technique must be dropped just because it leads to a solution
what solver, human or machine, ignores such gifts?

anyway, I defined P to have 3 outcomes and to use them
its most definately a mechanical / brute force technique
devised to characterize puzzles when combined with batched moves
it gives a reasonable estimate on the difficulties tree search and other
solvers would have arriving at a solution
and it maps back to terms familiar to me way back in grad school w.r.t.
ai / image processing / constraint satisfaction / backtrack search problems

just to be clear: I didn't define P to be the next greatest technique
its a means to characterize and parameterize the current batch of hard problems
in terms of the basic techiques in scope
gsf
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Location: NJ USA

gsf wrote:anyway, I defined P to have 3 outcomes and to use them

I suppose "P(FN-G)", for example, could be used to ignore the solution outcome ... but apparently I'm the only one who wishes to do so.
ronk
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ronk wrote:
gsf wrote:anyway, I defined P to have 3 outcomes and to use them

I suppose "P(FN-G)", for example, could be used to ignore the solution outcome ... but apparently I'm the only one who wishes to do so.

that would probably be the notation
but currently P(FN) is equivalent to P(FN-G)
I'll wait to see if P propositions lead anywhere before adding more options to it
gsf
2014 Supporter

Posts: 7306
Joined: 21 September 2005
Location: NJ USA

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