const FACTS = [
  ['bird', 'isa', 'animal'],
  ['pet', 'isa', 'animal'],
  ['canary', 'isa', 'bird'],
  ['penguin', 'isa', 'bird'],
  ['animal', 'can-fly', 'no'],
  ['bird', 'can-fly', 'yes'],
  ['penguin', 'can-fly', 'no'],
  ['tweety', 'isa', 'canary'],
  ['tweety', 'isa', 'pet'],
  ['chilly', 'isa', 'penguin'],
];

const foo = x => ([
  x, 
  ...FACTS.flatMap(fact => (
    x === fact[0] && 'isa' === fact[1] ? foo(fact[2]) : []
  ))
]);

// for testing; ignore
const showAll = () => {
  ['animal', 'bird', 'canary', 'tweety', 'penguin', 'chilly'].forEach(x => {
    console.log(`${x} => ${foo(x)}`);
  });
};