# Relationship history for MSHA mine 5400307

Current hierarchy: **Eugenio Perez  Matos → Gravero Ingenio Corp → Gravero Ingenio Corporation**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Ar-Ka Inc → Gravero Ingenio Corporation; 1988-05-01 to 1989-05-13; source msha-controller-operator-history
- **controller_controls_mine:** Sardinas Alfredo → Gravero Ingenio Corporation; 1988-05-01 to 1989-05-13; source msha-controller-operator-history
- **controller_controls_operator:** Sardinas Alfredo → Ar-Ka Inc; 1988-05-01 to 1989-05-13; source msha-controller-operator-history
- **operator_operates_mine:** Gravero Ingenio Corp → Gravero Ingenio Corporation; 1989-05-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Eugenio Perez  Matos → Gravero Ingenio Corporation; 1989-05-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eugenio Perez  Matos → Gravero Ingenio Corp; 1989-05-14 to current/open; source msha-controller-operator-history