SWI-Prolog -- distinct/1

Documentation
- Reference manual
  - The SWI-Prolog library
    - library(solution_sequences): Modify solution sequences
      - distinct/1
      - distinct/2
      - reduced/1
      - reduced/3
      - limit/2
      - offset/2
      - call_nth/2
      - order_by/2
      - group_by/4
- Packages

dt class="pubdef">distinct(:Goal)