| Twenty Years of Theorem Proving for HOLs Past, Present and Future Recent countries visiting this post |  |
 | 5 | United States |
 | 1 | |
 | 1 | Russian Federation |
| Twenty Years of Theorem Proving for HOLs Past, Present and Future Recent countries visiting this post | |
| 5 | United States |
| 1 | |
| 1 | Russian Federation |