# Libtmux.Expr.Rel.is

- **Module:** Libtmux.Expr
- **Package:** libtmux
- **Language:** OCaml
- **Kind:** function
- **Source:** https://github.com/libtmux/libtmux-ocaml/blob/205dfda49742592b479247049d186956e4a4cfe9/lib/libtmux.mli#L619
- **Public owner:** Libtmux
- **Page:** https://libtmux.org/en/ocaml/latest/reference/libtmux-expr-rel-is/

```
val is : ('a, 'b) Relation.One.t -> 'b t -> 'a t
```

## Parameters

- `arg1` (`('a, 'b) Relation.One.t`)
- `arg2` (`'b t`)