Some questions about Petrus' step 5-6.

[Tournevyks]

Hi,
I'm currently learning Petrus Method, but I have some troubles with steps 5 and 6. Firstly, I need some precisions about this sentence from Lars Petrus :

"Note that Niklas™ twists the corners in the same way as Sune™ does, so the same "target" rules apply. A Niklas™ that hits a target starts with the same turn as a Sune™ that hits the same target. About half the time you can avoid one Sune™ this way. "

When doing a Niklas, you have to permute 2 corners. But if, for instance, you want to permute FLU and BLU, you HAVE to begin your Niklas by 'R'. I don't see the way to avoid any Sune, as the way of doing a Niklas is imposed...

Secondly, Lars states that step 6 can always be done with 2 Sunes or less. But sometimes, it takes me 3 Sunes to finish it. I wonder if I really understand what a Sune is... Is it only The algorithm beginning with RUR'U..., or also his mirrored image ? I'm asking because I've checked some step 5+6, and some algos aren't done the same way as the main tutorial. For instance, the Sune of the Bq case (http://www.lar5.com/cube/yB.html) seems to be actually a reversed one...

I hope my questions aren't too understandable...
Thanks.

 

[Waynilein]

If you want to switch FLU and BLU, you can do Niklas as either R U' L' U R' U' L or as R' U L U' R U L'. Depending on how the corners are oriented, you can sometimes skip the orientation step by choosing the right kind of Niklas.

Depending on the context, Sune can mean one of four algorithms:
R U R' U R U2 R'
R' U' R U' R' U2 R
R U2 R' U' R U' R'
R' U2 R U R' U R
Basically, the Sune either reversed, mirrored, or both.

 

[Tournevyks]

Thanks for theses answers. It's strange Lars Petrus doesn't explain it like this... To me, a Sune was simply the algorithm he showed... I'm sure I'm not the only one who's been trapped by this... I hope so !
Then, if Sune means in fact "Sune, Sune Reversed, Sune backwards, Sune Reversed Backwards", what does "AntiSune" mean ? It seems to be Sune backward and reversed, but Waynilein says that "Sune backward reversed" is in fact a Sune...
Is there a precise reason why he chose to call four different algorithms the same way ? Ok, they look the same, but why not a Sune, a Sune backward, a Sune mirror, and so on ?

 

[JLarsen]

There are multiple variations of the sune. Anti sune is merely the inverse of a sune, or a sune backwards in other words. People refer to them merely as different algs because each one actually solves an OLL case, these being double sune/antisune, and the single sune/antisune cases. All that is being done during mirrored sunes or "sunes on the back" or even sunes just rotated, is that they are being done from different angles. They are indeed still a sune.