- #26

Hurkyl

Staff Emeritus

Science Advisor

Gold Member

- 14,916

- 19

**R**:

1. The empty set (everything is rejected)

2.

**R**(everything is accepted)

3. The set whose membership relation is always "no answer".

However, other definitions for real numbers (e.g. nested sequence of intervals whose endpoints are rational and whose length goes to zero) would allow more interesting subsets of

**R**.