Difference between revisions of "Talk:Predicate"
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In the framework of the set theory like ZF(C), one does not write that ''x'' belongs to a predicate, since in a set theory like NB(G) the class of all such ''x'' need not be a set, and in ZF(C) there is no notion of class. [[User:Boris|Boris]] ([[User talk:Boris|talk]]) 19:05, 18 March 2016 (UTC) | In the framework of the set theory like ZF(C), one does not write that ''x'' belongs to a predicate, since in a set theory like NB(G) the class of all such ''x'' need not be a set, and in ZF(C) there is no notion of class. [[User:Boris|Boris]] ([[User talk:Boris|talk]]) 19:05, 18 March 2016 (UTC) | ||
| + | : I like the axiomatic approach of ZF (I'm scared of C!) so I am confident with sets, I am not sure what a class is<sup>[1]</sup>, do you have any recommended reading? [[User:Alec|Alec]] ([[User talk:Alec|talk]]) 19:16, 18 March 2016 (UTC) | ||
| + | ::# At the moment I think of a class as "a collection defined to have a property, which is shown to be non empty". | ||
| + | :: If you do not hate it too much :-) look at WP: [https://en.wikipedia.org/wiki/Set_theory#Axiomatic_set_theory]: "Such systems come in two flavors, those whose ontology consists of: * Sets alone; ** Sets and proper classes. These include Von Neumann–Bernays–Gödel set theory,..." [[User:Boris|Boris]] ([[User talk:Boris|talk]]) 20:22, 18 March 2016 (UTC) | ||
Latest revision as of 20:22, 18 March 2016
In the framework of the set theory like ZF(C), one does not write that x belongs to a predicate, since in a set theory like NB(G) the class of all such x need not be a set, and in ZF(C) there is no notion of class. Boris (talk) 19:05, 18 March 2016 (UTC)
- I like the axiomatic approach of ZF (I'm scared of C!) so I am confident with sets, I am not sure what a class is[1], do you have any recommended reading? Alec (talk) 19:16, 18 March 2016 (UTC)
- At the moment I think of a class as "a collection defined to have a property, which is shown to be non empty".
- If you do not hate it too much :-) look at WP: [1]: "Such systems come in two flavors, those whose ontology consists of: * Sets alone; ** Sets and proper classes. These include Von Neumann–Bernays–Gödel set theory,..." Boris (talk) 20:22, 18 March 2016 (UTC)
