engine_next/2

Documentation
- Reference manual
  - Coroutining using Prolog engines
    - Engine predicate reference
- Packages

Availability:built-in

[semidet]engine_next(+Engine, -Term)

Ask the engine Engine to produce a next answer. On this first call on a specific engine, the Goal of the engine is started. If a previous call returned an answer through completion, this causes the engine to backtrack and finally, if the engine produces a previous result using engine_yield/1, execution proceeds after the engine_yield/1 call.