# at

At

x@y

**at** is a primitive that unifies list indexing, function application, and dictionary lookup into a single concept. Syntactically, it can be expressed in three equivalent ways: `x@y`

(using `@`

as a verb), `x y`

(juxtaposition of nouns), and `x[y]`

(M-expression).

"abc"[1] "b" {1+2*x}@3 7 (`a`b!0 1)`b 1

If `y`

is an atom not in the domain of `x`

, at returns the null value for `x`

's type (except in kona).