70 ms·
https://math.stackexchange.com/questions/1885938/whats-meaning-of-the-inverted-greek-letter-iota-%CE%B9-in-principia-mathematica-i https://math.stackexchange.co
by eesmith 2y ago
https://math.stackexchange.com/questions/1885938/whats-meaning-of-the-inverted-greek-letter-iota-%CE%B9-in-principia-mathematica-i https://math.stackexchange.com/questions/1885938/whats-meani... says 'in the article Frege, Peano and Russell on Descriptions: a Comparison, Francisco A. Rodríguez-Consuegra tracks down the source to Peano's Studii di logica matematica (1897) as where the operator first appears'
That page in 'Studii di logica matematica' appears to be https://archive.org/details/peano-studii-di-logica-matematica/page/18/mode/2up https://archive.org/details/peano-studii-di-logica-matematic... .
It also uses an upside-down C and upside-down E.
- Archelaos 2y agoAnd the Lambda looks like an upside-down V. The bases of all these upside-down letters do not match the baseline of the text. Obviously there were no special upside-down moveable types available of freshly cast for this book. Peano had to creatively repurpose what types were available.