Take the following as truth: The army of Juan I of Castile invaded Portugal in 1383, but Joao of Avis, recently proclaimed King Joao I of Portugal, defeated the Spaniards in a decisive battle which was fought in 1385 at Aljubarrota, about 100km (62 miles) north of Lisbon.
Then the following statement: "The Spaniards returned one year later." is true, false, or inconclusive?
Answer: Inconclusive