## Project: Well partial ordenings in proof theory and maximal order types

- project duration
- 01-OCT-11 – 30-SEP-13
- abstract
- The most important code for a mathematical proof system from logic is the proof-theoretic ordinal. In many cases, this proof-theoretic ordinal can be calculated as the maximal order type of a well partial ordening (hereafter wpo). We will investigate wpo's of (non-ordered) trees, wpo's in mathematical practice (e.g. in reverse mathematics and proof theory) and phase transitions concering wpo's.