display all the ideas for this combination of texts
4 ideas
23626 | Transfinite ordinals are needed in proof theory, and for recursive functions and computability [Hossack] |
9949 | There is the concept, the object falling under it, and the extension (a set, which is also an object) [Frege, by George/Velleman] |
23621 | Numbers are properties, not sets (because numbers are magnitudes) [Hossack] |
23622 | We can only mentally construct potential infinities, but maths needs actual infinities [Hossack] |