Constant lambda_calculus::term::UD
[−]
[src]
pub const UD: Term=
Var(0)
An undefined term that can be used as a value returned by invalid/inapplicable operations, e.g.
obtaining an element of an empty list. Since this implementation uses De Bruijn indices greater
than zero, Var(0)
will not occur naturally. It is displayed as undefined
.