| Merge: | set-Merge |
| Stream: | ['buy', 'v*', ['n_sg_3rd', 'mary'], 'Tpast', 'C_Q'] |
| Unlabeled: | |
| Box: |
| Merge: | set-Merge |
| Stream: | ['v*', ['n_sg_3rd', 'mary'], 'Tpast', 'C_Q'] |
| Unlabeled: |
| Merge: | set-Merge |
| Stream: | [['n_sg_3rd', 'mary'], 'Tpast', 'C_Q'] |
| Operations: | Checked Features: 'uPerson' 'uNumber' 'uGender' |
| Unlabeled: | |
| Label from Head: | |
| Label from Head: | |
| Label from Head: |
| Merge: | set-Merge |
| Stream: | [] |
| Unlabeled: |
| Merge: | set-Merge |
| Stream: | [['mary', 'n_sg_3rd'], 'Tpast', 'C_Q'] |
| Unlabeled: |
| Merge: | set-Merge |
| Stream: | ['C_Q'] |
| Operations: | Checked Features: 'uPerson' 'uNumber' 'uGender' |
| Unlabeled: |
| Merge: | set-Merge |
| Stream: | [] |
| Unlabeled: | |
| Label from Head: | |
| Label from Head: | |
| FormCopy: | |
| Access Box: | what+C_Q |
| Crash (Unlabeled): |
| Merge: | set-Merge |
| Stream: | [] |
| Unlabeled: |
| Merge: | set-Merge |
| Stream: | [] |
| Unlabeled: | |
| Label from Head: | |
| Label from Head: | |
| Label via shared features: | |
| Label from Head: | |
| Label from Head: | |
| FormCopy: | |
| Label via movement: | |
| FormCopy: | |
| Access Box: | what+C_Q |
| Transfer: | |
| Frontier: |
| Spell Out: | what+CQ n mary T(Past,3rd,sg) v* buy |
| PF Rules: | what CQ+T(Past,3rd,sg) what did mary buy |
| Merge: | set-Merge |
| Stream: | ['v*', ['n_sg_3rd', 'mary'], 'Tpast', 'C_Q'] |
| Unlabeled: |
| Merge: | set-Merge |
| Stream: | [['n_sg_3rd', 'mary'], 'Tpast', 'C_Q'] |
| Operations: | Checked Features: 'uPerson' 'uNumber' 'uGender' |
| Unlabeled: | |
| Label from Head: | |
| Label from Head: | |
| Label from Head: | |
| Label from Head: | |
| FormCopy: | |
| Crash (Unlabeled): |
| # of Merges: | 11 |
| # of Backtracks: | 2 |
| # of Crashes: | 10 |
| # of Successful Derivations: | 1 |