Assertion: filter's function | /r/HasProperty | defined pointwise modulo u
Facets:
value: by łoś' theorem
type: OTHER
Source sentences:
text: So instead the functions and relations are defined "pointwise modulo U", where U is an ultrafilter on the index set of the sequences; by Łoś' theorem, this preserves all properties of the reals that can be stated in first-order logic.