// b.sx authors its OWN `cfg` defaulting to 20. `from_b`'s `cfg()` omits the
// arg; the omitted trailing default must come from b.sx's author (20), not the
// first-wins winner from a.sx (10).
cfg    :: (n: s64 = 20) -> s64 { return n; }
from_b :: () -> s64 { return cfg(); }