# Vocabulary

The following page documents K related words. All definitions written here should be hence treated as such, and not as an extension of their English counterparts.

## Noun[edit]

A noun is a basic value in K, which can be a:

- Number
- Character
- Symbol
- Function
- Dictionary
- Array
- Table

## Verb[edit]

A verb is a primitive function in K. K has 20 primitive verbs which represent multiple overloads that form its base functionality.

## Adverb[edit]

An adverb is a primitive syntactical form in K which takes 1 or 2 functions on the left and changes their functionality.

## Dictionary[edit]

A K dictionary is a mapping from a set of K nouns as keys to a set of K nouns which constitute the values of the dictionary. Keys may not need to be unique, depending on the K version.

## Function[edit]

A function can be a:

- Primitive verb
- Lambda
- Train
- Projection of any of the above.

## Valence[edit]

The valence of a noun which supports application(function, array, dict) is the number of arguments it can take. K primitives are usually multi-valent and support different overloads for different valences.

## Monad[edit]

A Monad is a function which has valence 1 (single argument function).

## Dyad[edit]

A Dyad is a function which has valence 2 (two argument function).

## Matrix[edit]

A matrix is a 2D array (a list of lists) where all elements have the same length.

## Shape[edit]

The shape of an array is the length of each dimension in it.

## Conform[edit]

Conforming is a rule that applies to arithmetic verbs in K. A conforming operation is one which can take two arrays with arbitrary shape and line up each atom with a corresponding atom, preserving the structure of one of the given arguments. Conforming operations can only be done on arrays which recursively conform in terms of element length.

## Atomic[edit]

An atomic operation is one which can work on the lowest atoms of an array. Atoms can be one of:

- Integer
- Character
- Float
- Symbol

## Vector[edit]

A vector is a simple list that contains no subarrays.

## Scalar[edit]

A scalar is the smallest individual unit that can the added to an array, that is not an array. Otherwise this is See Atomic for the types of scalars.

## Lambda[edit]

The basic universal syntax for defining functions is the K lambda. A lambda with no arguments defined has its first three arguments stored in variables x, y and z. A lambda also has a variable for self reference (recursion).