Dyadic operator
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 (<syntaxhighlight lang=apl inline>∘</source>), and Power (<syntaxhighlight 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 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 (<syntaxhighlight lang=apl inline>+.× A</source> 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 <syntaxhighlight lang=apl inline>f∘g</source>, or a monadic function <syntaxhighlight lang=apl inline>A∘f</source> if an array <syntaxhighlight lang=apl inline>A</source> is bound to a function <syntaxhighlight lang=apl inline>f</source>.