Message #1192

From: Andrew Gould <>
Subject: RE: [MC4D] Re: Tetrahedral prism {3,3}x{}, 3 layers solved
Date: Thu, 30 Sep 2010 01:21:39 -0500

Re: 2) Actually, I just realized you can currently do this twist type in
the {3,3}x{} as long as the length is 3 (or greater). You can do it by
holding down ‘1’ & ‘2’ (or ‘1’ through [length - 1]) and clicking on one of
the 3C pieces (or 2C pieces) that only has triangular prism stickers.

3) Still looking at this twist type.

4) Mathematically it’s possible to twist a 2D triangle face by 120-degrees.
These are the 2D triangle faces where a 3D tetrahedron face and one of the
3D triangular prism faces meet. This includes (a) octahedral sticker(s), as
well as two lines (one right side up, one upside down) of triangular prism
stickers from each of the other three 3D triangular prism faces.


From: [] On Behalf
Of Andrew Gould
Sent: Wednesday, September 29, 2010 22:04
Subject: RE: [MC4D] Re: Tetrahedral prism {3,3}x{}, 3 layers solved

IIIIIII see now. So the triangular prism stickers that are part of 4C
pieces can’t be clicked on. I bet you’ll add 120-degree face twists to at
least the 2D triangle sides of the rectangular prism stickers.
Specifically, on the rectangular prisms of the {3,3}x{} 2 (where you can’t
click on any part of any rectangular prism sticker) you could add 180-degree
twists when clicking on their 2D rectangular faces and add 120-degree twists
to their 2D triangular faces. The idea is inspired by how you did 120 &
90-degree twists to the {4,3,3} 2.

I just imagined having multiple ways the user can choose between 90, 120,
and 180 degree twists (seeing as 180-degree twists aren’t possible on the
{4,3,3} 2). Possibly keyboard shortcuts like ‘A + Click’, ‘B + Click’, ‘C +
Click’, but also possibly (and/or) a third tab on the left side titled
‘twists’. In this, you could also add the 2D twist feature I have wished to

1) Speaking of which, last night I verified that some non-3D-face twists are
mathematically possible on the {3,3}x{}, like rotating only a 4C piece ALONE
by 120 degrees (no other piece moves nor twists).

2) Tonight I have found that on the {3,3}x{} 2 it’s also mathematically
possible to twist two 4C pieces alone by 180 degrees (they can’t have the
same color tetrahedron sticker–the two 4Cs would end up switching
location–if the side length were 3 or greater, then 3C pieces on the line
directly between them are also involved). It’s possible without grooves in
other stickers. Neither is any extra space needed between stickers.

3) I’m now looking at this one: Take a 3D face that isn’t a tetrahedron (so
it’s a bunch of rectangular prism stickers). Take one of the rectangular 2D
faces of that (most likely includes the upside down rectangular prisms that
are really close to that face). I’ll check if it’s possible to twist this
by 180 degrees.


From: [] On Behalf
Of Melinda Green
Sent: Wednesday, September 29, 2010 3:36
Subject: Re: [MC4D] Re: Tetrahedral prism {3,3}x{}, 3 layers solved


I’m not suggesting the removal of any records. I’m just asking that
solutions to unsupported puzzles be flagged as such because they’re at
increased risk of being later invalidated. This case may be perfectly safe
as you suggest but there are more reasons why we might not have felt
confident enough to support particular puzzles. For example, creating a
truly and properly scrambled state is not a trivial thing. It’s very easy to
not scramble it enough or to not use enough operators such as to reach all
types of states or to make certain types of scrambled states wildly more or
less likely.

Thanks for weighing in,

On 9/29/2010 1:22 AM, Galla, Matthew wrote:

There is only one parituclar type of move that you cannot make in 1 click on
the {3,3}x{}, 3 puzzle: the rotation of one of the triangular prism faces by
120 degrees. This move can, however, be accomplished in 2 moves (click a 2C
piece that faces another triangular prism and then click an edge piece[3C]
between 3 triangular prism faces on the same face as the first click)

Therefore, the bug doesn’t lose any states but does potentially change the
move count, depending on the solve of course. I think any record made on the
current implementation should stay becuase if anything, the bug makes the
record worse than it could have been.

Just my two cents :)

-Matt Galla

On Wed, Sep 29, 2010 at 12:29 AM, Melinda Green <>

I don’t know if there is or is not such a difference. Roice was the one
directly supporting the Don’s puzzle creation code so I mostly deferred to
his opinions in such matters while I’d veto puzzles with other problems such
as infinite loops while scrambling, etc. In general we didn’t include any
puzzles that didn’t get the thumbs up from both of us, therefore any puzzles
not in that set are considered unsupported. We’re both happy that people
explore outside these bounds of the supported set but you’re basically on
your own with them in that you risk losing your records if we end up
defining a particular puzzle differently from what you solved. It’s also not
up to us to prove whether such a change makes for a fundamentally different
puzzle. By adding your solution to the wiki’s firsts and shortests, it
becomes your responsibility to make sure that it’s accurate according to the
puzzle definitions that end up being supported. I suggest that until that
time you add an asterisk on the records page with a footnote flagging it as
a tentative record. I think that should hold for any more such solutions by
anyone. Alternatively, if you can convince Roice that the puzzle is well
defined and implemented, then we should add it to the supported list. Of
course if you’d like to work on extending the range of supported puzzles,
we’d love your help. Just note that Don has a more up-to-date engine that we
didn’t know about at the time and the task of incorporating that new engine
is our highest priority issue #94
<> . We’re just not
doing any development currently.


On 9/28/2010 10:02 PM, Andrey wrote:

Of course, when you show me the twist in new puzzle that can’t be
performed in the old one, I’ll agree that this puzzle is different. But now
I can’t imagine such twist )))


— In, Melinda Green <mailto:melinda@…>
<melinda@…> wrote:

I’m glad that you guys are having fun with the tetrahedral prisms but
I have to remind everyone that solutions to puzzles not included in the
menu must be considered as unofficial results, at least for ones that
are not trivial extensions to ones already there. Not all twists that
should be allowed on this puzzle are currently allowed, making it on one
hand harder to solve, but on the other hand, the scrambling may not
reach all possible positions, making it potentially easier to solve. I
think that we’ll have to consider any firsts or shortests as tentative
at best. Please do continue to explore experimental puzzle
s because this
is a great way to help us figure out how they should work. Just remember
that any such solutions are unofficial until they are added to the menu
of supported puzzles.



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