"This is a thought, therefore thoughts exist" is the valid, non-circular version. Let us cast this argument in formal logic. What are the axioms? What is the

"This is a thought, therefore thoughts exist" is the valid, non-circular version. Let us cast this argument in formal logic. What are the axioms? What is the conclusion? https://isabelle.in.tum.de https://isabelle.in.tum.de