Round 8: Tossup 11

In 2020, Scott Aaronson conjectured that the busy beaver function of 20 was the upper bound of what this system could prove. Shelah showed (10[1])that two implications of this system produce contradictory answers to the Whitehead problem. The first-order form of this system violates the Löwenheim–Skolem theorem, leading to Skolem’s paradox. In 1963, Paul Cohen used forcing (-5[1])to show that this system and the continuum hypothesis are independent of each other. (10[1])This system’s (10[1])inclusion of the axiom of specification allows it to avoid Russell’s paradox. The letter C (-5[1])is appended to this system’s name (10[1])to indicate its inclusion of the axiom of (10[1])choice. For 10 points, name this standard formulation of set theory proposed by two German mathematicians, often known (10[1])by a two-letter acronym. (0[1])■END■

Back to tossups

Buzzes

Summary