use specification_core::Specification;
fn main() {
let is_adult = |age: &u8| *age >= 18;
let is_retired = |age: &u8| *age >= 65;
let working_age = is_adult.and(is_retired.not());
assert!(working_age.is_satisfied_by(&42));
assert!(!working_age.is_satisfied_by(&17));
assert!(!working_age.is_satisfied_by(&70));
}