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null_intersection                                                (Lib)
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null_intersection : ''a list -> ''a list -> bool

SYNOPSIS
Tells if two lists have no common elements.

KEYWORDS
set, list, eqtype.

DESCRIBE
An invocation {null_intersection l1 l2} is equivalent to
{null(intersect l1 l2)}, but is more efficient in the case where
the intersection is not empty.

FAILURE
Never fails.

EXAMPLE

- null_intersection [1,2,3,4] [5,6,7,8];
> val it = true : bool

- null_intersection [1,2,3,4] [8,5,3];
> val it = false : bool




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

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

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