# TwoWayRule

x<->y or xy

represents a two-way rule expressing exchange or correspondence of x and y.

# Details

• Two-way rules are very general constructs that can represent exchange, equivalence, correspondence and other bidirectional relations between expressions.
• The character can be entered as [TwoWayRule].
• In StandardForm, TwoWayRule is printed using .
• Transpose[array,nm] transposes levels n and m of the array, without changing other levels.
• TwoWayRule[a,b] is equivalent to UndirectedEdge[a,b] in Graph constructors.

# Examples

## Basic Examples(2)

Exchange levels 2 and 3 of an array of depth 3 using TwoWayRule to express a permutation:

Input undirected edges in a graph using TwoWayRule:

Wolfram Research (2017), TwoWayRule, Wolfram Language function, https://reference.wolfram.com/language/ref/TwoWayRule.html.

#### Text

Wolfram Research (2017), TwoWayRule, Wolfram Language function, https://reference.wolfram.com/language/ref/TwoWayRule.html.

#### CMS

Wolfram Language. 2017. "TwoWayRule." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/TwoWayRule.html.

#### APA

Wolfram Language. (2017). TwoWayRule. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/TwoWayRule.html

#### BibTeX

@misc{reference.wolfram_2024_twowayrule, author="Wolfram Research", title="{TwoWayRule}", year="2017", howpublished="\url{https://reference.wolfram.com/language/ref/TwoWayRule.html}", note=[Accessed: 17-July-2024 ]}

#### BibLaTeX

@online{reference.wolfram_2024_twowayrule, organization={Wolfram Research}, title={TwoWayRule}, year={2017}, url={https://reference.wolfram.com/language/ref/TwoWayRule.html}, note=[Accessed: 17-July-2024 ]}