“What if it could not go through?” Tao asked. Grandpa Song nodded. This was a different imagined case, not one result changing into another, and not both happening at once.

Ahe looked at his toy spear. Then there would be a shield it could not pierce. He could no longer say it could pierce every shield. His second claim was too large as well.

“So I cannot just choose the answer I like,” Ahe said. Grandpa Song smiled. “Those two claims cannot both be true.” They had not tested the toys' strength. They had found the contradiction in the words.