hereditarily finite sets造句
例句与造句
- The set of all well-founded hereditarily finite sets is denoted " V " ?.
- It is V _ \ omega \ !, the class of hereditarily finite sets, with the inherited element relation.
- The hereditarily finite sets, V ?, satisfy the axiom of regularity ( and all other axioms of ZFC except the axiom of infinity ).
- Mainstream mathematicians consider strict finitism too confining, but acknowledge its relative consistency : the universe of hereditarily finite sets constitutes a model of Zermelo Fraenkel set theory with the axiom of infinity replaced by its negation.
- One can interpret the theory of hereditarily finite sets within Peano arithmetic ( and certainly also vice versa ), so the incompleteness of the theory of Peano arithmetic implies that of the theory of hereditarily finite sets.
- It's difficult to find hereditarily finite sets in a sentence. 用hereditarily finite sets造句挺难的
- One can interpret the theory of hereditarily finite sets within Peano arithmetic ( and certainly also vice versa ), so the incompleteness of the theory of Peano arithmetic implies that of the theory of hereditarily finite sets.
- For any finite ordinal n, the sets L n and V n are the same ( whether V equals L or not ), and thus L ? = V ? : their elements are exactly the hereditarily finite sets.
- Instead of being considered as a subset of the natural numbers, it is also possible to encode 0 # as a subset of formulae of a language, or as a subset of the hereditarily finite sets, or as a real number.
- We regain the two simple notions we introduced above as H ( \ omega ) being the set of hereditarily finite sets and H ( \ omega _ 1 ) being the set of hereditarily countable sets . ( \ omega _ 1 is the first uncountable ordinal .)
- The existence of Grothendieck universes ( other than the empty set and the set V _ \ omega of all hereditarily finite sets ) is not implied by the usual ZF axioms; it is an additional, independent axiom, roughly equivalent to the existence of strongly inaccessible cardinals.
- Notice that there are countably many hereditarily finite sets, since " V n " is finite for any finite " n " ( its cardinality is " n " & minus; 1 2, see tetration ), and the union of countably many finite sets is countable.
- A seeming paradox, non-standard models of the theory of hereditarily finite sets contain infinite sets---but these infinite sets look finite from within the model . ( This can happen when the model lacks the sets or functions necessary to witness the infinitude of these sets . ) On account of the incompleteness theorems, no first-order predicate, nor even any recursive scheme of first-order predicates, can characterize the standard part of all such models.