CONTEXT simple_sets_ctx
SETS
    PERSONS ITEMS
CONSTANTS
    all_persons all_items person_limit
AXIOMS
    @axm1 all_persons <: PERSONS
    @axm2 all_items <: ITEMS
    @axm3 person_limit = 100
    @axm4 person_limit > 0
THEOREMS
    @thm1 all_persons ∪ all_items = {}
END
