## A.55 library(tables): XSB interface to tables

This module provides an XSB compatible library to access tables as created by tabling (see table/1). The aim of this library is first of all compatibility with XSB. This library contains some old and internal XSB predicates that are marked deprecated.

tnot(:Goal)
  Tabled negation.
  deprecated
    This is a synonym to tnot/1.
tfindall(+Template, :Goal, -Answers)
  This predicate emerged in XSB in an attempt to provide a safer alternative to findall/3. This doesn't really work in XSB and the SWI-Prolog emulation is a simple call to findall/3. Note that Goal may not be a variant of an incomplete table.
  deprecated
    Use findall/3
set_pil_on
set_pil_off
  Dummy predicates for XSB compatibility.
  deprecated
    These predicates have no effect.
[semidet]get_call(:CallTerm, -Trie, -Return)
  True when Trie is an answer trie for a variant of CallTerm. Return is a term ret/N with N variables that share with variables in CallTerm. The Trie contains zero or more instances of the Return term. See also get_calls/3.
[nondet]get_calls(:CallTerm, -Trie, -Return)
  True when Trie is an answer trie for a variant that unifies with CallTerm and Skeleton is the answer skeleton. See get_call/3 for details.
[nondet]get_returns(+ATrie, -Return)
  True when Return is an answer template for the AnswerTrie.

  Return | is a term `ret(...)`. See get_calls/3.

[nondet]get_returns(+AnswerTrie, -Return, -NodeID)
  True when Return is an answer template for the AnswerTrie and the answer is represented by the trie node NodeID.

  Return | is a term `ret(...)`. See get_calls/3.

[nondet]get_returns_and_tvs(+AnswerTrie, -Return, -TruthValue)
  Identical to get_returns/2, but also obtains the truth value of a given answer, setting TruthValue to `t` if the answer is unconditional and to `u` if it is conditional. If a conditional answer has multiple delay lists, this predicate will succeed only once, so that using this predicate may be more efficient than get_residual/2 (although less informative)
[nondet]get_returns_and_dls(+AnswerTrie, -Return, :DelayLists)
  True when Return appears in AnswerTrie with the given DelayLists. DelayLists is a list of lists, where the inner lists expresses a conjunctive condition and and outer list a disjunction.
[nondet]get_residual(:CallTerm, -DelayList)
  True if CallTerm appears in a table and has DelayList. SWI-Prolog's representation for a delay is a body term, more specifically a disjunction of conjunctions. The XSB representation is non-deterministic and uses a list to represent the conjunction.

  The delay condition is a disjunction of conjunctions and is represented as such in the native SWI-Prolog interface as a nested term of ;/2 and ,/2, using `true` if the answer is unconditional. This XSB predicate returns the associated conjunctions non-deterministically as a list.

  See also call_residual_program/2 from `library(wfs)`.

[nondet]get_returns_for_call(:CallTerm, -AnswerTerm)
  True if AnswerTerm appears in the tables for the variant CallTerm.
abolish_table_pred(:CallTermOrPI)
  Invalidates all tabled subgoals for the predicate denoted by the predicate or term indicator Pred.
  To be done
    If Pred has a subgoal that contains a conditional answer, the default behavior will be to transitively abolish any tabled predicates with subgoals having answers that depend on any conditional answers of S.
[det]abolish_table_call(+Head)
[det]abolish_table_call(+Head, +Options)
  Same as abolish_table_subgoals/1. See also abolish_table_pred/1.
  deprecated
    Use abolish_table_subgoals/[1,2].
abolish_table_subgoals(:Head, +Options)
  Behaves as abolish_table_subgoals/1, but allows the default `table_gc_action` to be over-ridden with a flag, which can be either `abolish_tables_transitively` or `abolish_tables_singly`.
  Compatibility
    Options is compatible with XSB, but does not follow the ISO option handling conventions.