| Original language | English (US) |
|---|---|
| Pages (from-to) | 179-187 |
| Number of pages | 9 |
| Journal | Annals of Mathematical Logic |
| Volume | 2 |
| Issue number | 2 |
| DOIs | |
| State | Published - Oct 1970 |
| Externally published | Yes |
Bibliographical note
Funding Information:* While working on this paper, the author was supported by the National Science Foundation, Grant GP-14569 at the University of Wisconsin, Madison.