Comment by nitrix | Hacker News Reader

Comment by nitrix | Hacker News Reader

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Of course backtracking isn't only a subject of logical programming, what made you think that when reading my reply?

The use of "when your logic" doesn't limit you to programming languages or imply that one is involved.

I'm not sure why you feel the need to unnecessarily correct me on that.

Also, of course the definition is quite general and, of course, Prolog is famous for excelling at it. Those are precisely the reasons why I mentioned all of the things that I did, in the way that I did.

I really don't understand why you think it's necessary to put emphasis on that a second time.

Avoiding 1,1,1, in a code like this

   for x1 in range(1, 10):
        for x2 in range(1, 10):
            if x2 in [x1]:
                continue
            for x3 in range(1, 10):
                if x3 in [x1, x2]:
                    continue

looks like backtracking to me. Specifically, the "continue" statement is that "jump back" that prunes invalid search sub-tree. Though, the constrains are expressed as predicates here.

But even in a code where constrains are built into the loop, it also can be called backtracking, since we have our target predicate "is_valid(square)". The search tree is trivial in this case, though. It's just a root and leaves.

In other words, I didn't quite understand the distinction that you were talking about.

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