\DOC set_eq

\TYPE {set_eq : ''a list -> ''a list -> bool}

\SYNOPSIS
Tells whether two lists have the same elements.

\KEYWORDS
set, list, eqtype.

\DESCRIBE
An application {set_eq l1 l2} returns {true} just in case {l1} and {l2}
are permutations of each other when duplicate elements within each list
are ignored.

\FAILURE
Never fails.

\EXAMPLE
{
- set_eq [1,2,1] [1,2,2,1];
> val it = true : bool

- set_eq [1,2,1] [2,1];
> val it = true : bool
}


\COMMENTS
A high-performance implementation of finite sets may be found in
structure {HOLset}.

ML equality types are used in the implementation of {set_eq}
and its kin. This limits its applicability to types that
allow equality. For other types, typically abstract ones,
use the `op_' variants.

\SEEALSO
Lib.intersect, Lib.union, Lib.U, Lib.mk_set, Lib.mem, Lib.insert, Lib.set_diff.

\ENDDOC