proper-subset? ( set1 set2 -- ? )

Vocabulary

sets.extras

Inputs

set1	a set
set2	a set

Outputs

?

a boolean

Word description

Find whether set1 is a proper subset of set2. Returns true if set1 is a subset of set2 but set2 is not a subset of set1.

Definition

USING: kernel sets ;

IN: sets.extras

: proper-subset? ( set1 set2 -- ? )
    2dup subset? [ swap subset? not ] [ 2drop f ] if ;