digraph TEST_SUB {
    FUNC [module=test_funcs.simplest, entry_func=increment_a_edge]
    PRED [module=test_funcs.simplest, entry_func=positiveness_predicate]
    MORPH [predicate=PRED, function=FUNC]
    SEL [module=test_funcs.simplest, entry_func=selector_a_nonpositive]
    
    ST2 [subgraph = tests/adot/file.adot]
    ST3 [selector = SEL]

    __BEGIN__ -> ST1 [morphism = MORPH]
    ST1 -> ST2 
    ST2 -> ST3 
    ST3 -> __END__ 
}