clause/2

Documentation
- Reference manual
  - Built-in Predicates
    - Examining the program
- Packages

Availability:built-in

[ISO]clause(:Head, ?Body)

True if Head can be unified with a clause head and Body with the corresponding clause body. Gives alternative clauses on backtracking. For facts, Body is unified with the atom true. Note that SWI-Prolog allows clause/2 to work on both dynamic and static code.^{95Using clause/2
is disallowed if either the flag iso
or protect_static_code
is true.} Note that clause/2 decompiles the actual clause and may return a clause that is different from the source or asserted clause, i.e., clause/2 only promises semantic equivalence.