Packet 8: Tossup 18
Researchers at Cambridge and Munich developed the Isabelle system for this task, which uses an HOL approach that is based on the earlier LCF system created by Robert Milner. Setups for this task are often also used as solvers for SMT. This task can be performed on well-formed recursively enumerable inputs using the DPLL algorithm. The outputs of this task are visualized by a semantic tableau, on which intermediate results are simplified using unification and resolution. The programming language ML was developed for this task, which is equivalent to functional programming by the Curry–Howard isomorphism. An “interactive” approach to this task can be performed using Lean or Rocq. For 10 points, 1,834 reducible configurations were checked by a computer to allow Appel and Haken to do what task for the four-color theorem? ■END■
Buzzes
Summary
| Tournament | Edition | Match | Heard | Conv. % | Neg % | Avg. Buzz |
|---|---|---|---|---|---|---|
| Main Site | 2026-04-17 | ✓ | 20 | 90% | 25% | 98.39 |