Understanding Intuitionism by Edward Nelson Department of Mathematics Princeton University Intuitionism was the creation of L. E. J. Brouwer [Br], and I like to think that classical mathematics was the creation of Pythagoras. Imag- ine a conversation between a classical mathematician and an intuitionist, say a woman and a man respectively. She speaks first: I have just proved ∃xA. Congratulations! What is it? I don't know. I assumed ∀x¬A and derived a contradiction.
- classical formulas
- equality axioms
- intuitionistic semantics
- substitution axiom schemes of the predicate calculus
- time to time for input
- proof
- rules
- 3 c.
- c.