Valence

From The K Language Wiki

Valence, a.k.a. arity or adicity, is the number of arguments a function accepts.

The minimum valence of a k function is 1 and the maximum is 8.

Applying a function to fewer arguments creates a projection. Applying it to more arguments usually causes a rank error, though some primitives may support more arguments than their nominal valence.

The following Greek and Latin-based English words are commonly used to describe a function of a particular valence[1]:

Greek Latin
1 monadic unary
2 dyadic binary
3 triadic ternary
4 tetradic quaternary