As I solve puzzles, I frequently use AIC that consider exactly 3 strong inference sets. By that I mean, 3 sets upon which I use the strong inference. All of these can be represented with one common idea. Almost all of them are completely analagous to the standard Y wing, thus the name, Y Wing Styles.

Some of them are easier to find than the standard Y wings. As a group, many of them occur much more frequently than standard 3 bivalue cell Y wings. None of them are something new, by and of themselves.

Nevertheless, considering all of them as part of a simple whole:

A strong inference set as the vertex, with two strong inference sets as the endpoints - thus forming a Y, is a very simple but powerful tool.

Added Detail:

Here is a broad and very general explanation of the idea, Y Wing Styles:

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`Consider exacly three native sets upon which one can perform a Strong Inference.`

View one or more of these three sets as a vertex.

Using only the base set of puzzle constraints, prove one or more non-native sets which satisfies the strong inference requirement.

Make eliminations based upon these newly proven (non-native) strong inference sets.

Native : naturally occurring in the current puzzle possibility matrix.

Many puzzles that I have found with suggested solutions completely ignore the existence of most of these Y Wing Styles.

One of the types of Y wing Styles, that I call in my blog as being very common, is not only more common than the standard Y wing, but also much easier to find.

I have a number of pages in my sudoku blog that deal extensively with this concept. Also, I have a number of puzzle proofs that use this concept as the primary solving tool for that particular puzzle (but rarely the only solving tool).

The nomenclature that I use to describe many of the ideas commonly used in this forum is a bit non-standard. Nevertheless, the nomenclature is well described within my blog and hopefully easy to decipher.

If this concept is of any interest to those who frequent this forum, I can add more details here later.

To investigate Y Wing Styles, the two following web pages of my blog are probably fair (slightly better than poor) places to start:

http://sudoku.com.au/YWingStyle.aspx

http://sudoku.com.au/YWingStyle2.aspx