# Difference between revisions of "Dyadic operator"

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− | In [[APL syntax]], a '''dyadic operator''' (or '''conjunction''') is an [[operator]] which takes two [[operand]]s, one on each side. In [[APL\360]] the only dyadic operator was [[Inner Product]], but other operators such as [[Power (operator)|Power]] | + | In [[APL syntax]], a '''dyadic operator''' (or '''conjunction''') is an [[operator]] which takes two [[operand]]s, one on each side. In [[APL\360]] the only dyadic operator was [[Inner Product]], but other operators such as [[Beside]] and [[Bind]] (<source lang=apl inline>∘</source>), and [[Power (operator)|Power]] (<source lang=apl inline>⍣</source>) have become common, and languages such as [[J]], [[NARS2000]], and [[dzaima/APL]] have added many experimental dyadic operators. |

The term "dyadic operator" refers to the [[operator valence|valence]] of the operator itself, that is, the number of operands. When applied, it produces a [[derived function]], which can have a different [[function valence]]. For example, the [[Inner Product]] is usually a dyadic operator that produces a [[dyadic function]] (<source lang=apl inline>+.× A</source> is a [[SYNTAX ERROR]], unless it's defined to be the [[Determinant]] operator), while [[Power (operator)|Power]] generally produces an [[ambivalent]] function. The [[Compose]] function can produce an ambivalent function <source lang=apl inline>f∘g</source>, or a monadic function <source lang=apl inline>A∘f</source> if an array <source lang=apl inline>A</source> is [[Bind|bound]] to a function <source lang=apl inline>f</source>. | The term "dyadic operator" refers to the [[operator valence|valence]] of the operator itself, that is, the number of operands. When applied, it produces a [[derived function]], which can have a different [[function valence]]. For example, the [[Inner Product]] is usually a dyadic operator that produces a [[dyadic function]] (<source lang=apl inline>+.× A</source> is a [[SYNTAX ERROR]], unless it's defined to be the [[Determinant]] operator), while [[Power (operator)|Power]] generally produces an [[ambivalent]] function. The [[Compose]] function can produce an ambivalent function <source lang=apl inline>f∘g</source>, or a monadic function <source lang=apl inline>A∘f</source> if an array <source lang=apl inline>A</source> is [[Bind|bound]] to a function <source lang=apl inline>f</source>. | ||

{{APL syntax}} | {{APL syntax}} |

## Revision as of 18:44, 26 April 2020

In APL syntax, a **dyadic operator** (or **conjunction**) is an operator which takes two operands, one on each side. In APL\360 the only dyadic operator was Inner Product, but other operators such as Beside and Bind (`∘`

), and Power (`⍣`

) have become common, and languages such as J, NARS2000, and dzaima/APL have added many experimental dyadic operators.

The term "dyadic operator" refers to the valence of the operator itself, that is, the number of operands. When applied, it produces a derived function, which can have a different function valence. For example, the Inner Product is usually a dyadic operator that produces a dyadic function (`+.× A`

is a SYNTAX ERROR, unless it's defined to be the Determinant operator), while Power generally produces an ambivalent function. The Compose function can produce an ambivalent function `f∘g`

, or a monadic function `A∘f`

if an array `A`

is bound to a function `f`

.