In the year 2014, both Peter Koepke and Philip Welch are celebrating their 60th birthdays, and this festive occasion is celebrated with this Festschrift in their honour containing scientific contributions of their students, collaborators, colleagues and friends which cover the various different research ares of logic in which Peter and Philip are active. | Infinity Computability and Metamathematics by Stefan Geschke, Hardcover | Indigo Chapters