jump to navigation

The state of Seqsee December 11, 2006

Posted by amahabal in Uncategorized.
trackback

This entry will try to pinpoint what is still not done in Seqsee. Here is the programme: I will trot out a sequence at a time and point out whether Seqsee would get that, and if the answer is no talk about what the missing pieces are. Often, it is not so much that pieces are missing as that they have not been fit into the puzzle.

 

1 2 3 4 5…

 

Yes, Seqsee gets this. I wanted to put in at least one thing that works.

 

1…

 

Nope, not just yet! This requires a piece that sits half-built in my workshop: long-term memory. By long-term I mean a memory capable of remembering things between runs. One of the next few entries will spell out what I am thinking.

 

1 1 2 3 1 2 2 3 4 1…

 

Yes, kind of. Seqsee sometimes gets this, but has a way of unseeingly staring at the solution. Rules will help it see this sort of thing much faster, and rules shall be the topic of an entry in the next couple of days.

 

2 15 16 1 2 3 8 9 10 11 5 6 7 8 9 11 12 13 14 15 16…

 

No. For most sequences that Seqsee shall deal with, the next term after seeing several terms is more or less well determined. Not in this case, though. The next seven terms will form an ascending group but it could be any such group. What is missing from Seqsee that prevents it from seeing such sequences is the notion of a weak relation. A weak relation is exactly of the sort present in the sequence: it under-determines the right hand side given the left-hand side. In this particular sequence, the relation is that the right hand side is also an ascending group but longer by one.

 

What is also missing is the ability to create random groups meeting a specification. In this particular case, the subsequent group has the specification “ascending group of length seven”. There are other less spelled out constraints like “the group shall start with a smaller number (and not 1 million)”.

 

A third bit that is missing is that I do not have a mechanism yet to look for a group meeting a specification already present in the workspace. Currently, since sequences that Seqsee deals with are deterministic, it is enough to check whether a particular thing is in the workspace at a particular point. I would need to extend that to be able to check whether that particular type of thing is in the workspace at a particular point.

 

1 1 2 3 1 2 2 3 1 2 3 3 1 1 2 3…

 

No! After the 12th term, Seqsee hits the big snag, and it has not yet learned to recover. Rules, again, are implicated in this.

 

All the foregoing might suggest that there is much that Seqsee cannot do. This is true: even when Seqsee solves all the sequences on this page it will be no less true (just as it is not true that people living in high-rise buildings are somehow closer to God). I do hope that by the time I am done with my Ph.D. Seqsee would at least get all these sequences.

Comments»

No comments yet — be the first.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: