#include <DefaultForwardChainerCB.h>

Inheritance diagram for opencog::DefaultForwardChainerCB:

Collaboration diagram for opencog::DefaultForwardChainerCB:

Public Member Functions
HandleSeq	substitute_rule_part (AtomSpace &as, Handle hrule, const std::set< Handle > &vars, const std::vector< std::map< Handle, Handle >> &var_groundings)

	DefaultForwardChainerCB (AtomSpace &as, source_selection_mode ts_mode=TV_FITNESS_BASED)

virtual vector< Rule * >	choose_rules (FCMemory &fcmem)

virtual HandleSeq	choose_premises (FCMemory &fcmem)

virtual Handle	choose_next_source (FCMemory &fcmem)

virtual HandleSeq	apply_rule (FCMemory &fcmem)

Public Member Functions inherited from opencog::ForwardChainerCallBack
	ForwardChainerCallBack (AtomSpace *as)

virtual	~ForwardChainerCallBack ()

Public Attributes
std::map< Handle, std::vector < Handle > >	rule_derivations

Private Member Functions
Handle	gen_sub_varlist (const Handle &parent, const Handle &parent_varlist)

HandleSeq	unify (Handle source, Handle target, Rule *rule)

HandleSeq	subatom_unify (Handle source, Rule *rule)

bool	is_valid_implicant (const Handle &h)

Private Attributes
AtomSpace &	_as

ForwardChainerPMCB	_fcpm

source_selection_mode	_ts_mode

Friends
class	::DefaultForwardChainerCBUTest

Detailed Description

Definition at line 36 of file DefaultForwardChainerCB.h.

Constructor & Destructor Documentation

DefaultForwardChainerCB::DefaultForwardChainerCB	(	AtomSpace &	as,
		source_selection_mode	ts_mode = `TV_FITNESS_BASED`
	)

Definition at line 41 of file DefaultForwardChainerCB.cc.

Member Function Documentation

HandleSeq DefaultForwardChainerCB::apply_rule ( FCMemory & fcmem )

virtual

apply chosen rule. the default will wrap a custom PM callback class. i.e invokes _pattern_matcher.

Returns: a set of handles created as a result of applying current choosen rule

Make sure the inferences made are new.

Implements opencog::ForwardChainerCallBack.

Definition at line 255 of file DefaultForwardChainerCB.cc.

References _fcpm, opencog::BindLinkCast(), createBindLink, opencog::FCMemory::get_cur_rule(), opencog::Rule::get_handle(), opencog::ForwardChainerPMCB::get_products(), opencog::Implicator::implicand, opencog::FCMemory::isin_potential_sources(), opencog::LinkCast(), and opencog::ForwardChainerPMCB::set_fcmem().

Handle DefaultForwardChainerCB::choose_next_source ( FCMemory & fcmem )

virtual

choose next source from the source list

Returns: a handle to the chosen source from source list

Choose a new source that has never been chosen before. xxx FIXME since same handle might be chosen multiple times the following code doesn't guarantee all sources have been exhaustively looked.

Implements opencog::ForwardChainerCallBack.

Definition at line 211 of file DefaultForwardChainerCB.cc.

References _as, _ts_mode, opencog::FCMemory::get_potential_sources(), opencog::FCMemory::isin_selected_sources(), opencog::STI_BASED, python.undocumented.blocksworld::t, opencog::URECommons::tournament_select(), opencog::URECommons::tv_fitness(), opencog::TV_FITNESS_BASED, and opencog::Handle::UNDEFINED.

HandleSeq DefaultForwardChainerCB::choose_premises ( FCMemory & fcmem )

virtual

Choose additional premises for the rule. an object holding the current source/target and other inform ation of the forward chaining instance.

Returns: a set of Handles chosen as a result of applying fitness criteria with respect to the current source.

Implements opencog::ForwardChainerCallBack.

Definition at line 186 of file DefaultForwardChainerCB.cc.

References _as, opencog::FCMemory::get_cur_source(), opencog::get_distant_neighbors(), and opencog::URECommons::get_root_links().

vector< Rule * > DefaultForwardChainerCB::choose_rules ( FCMemory & fcmem )

virtual

Choose rules based on implicant member of rule matching the source. Whenever a matching rule is found, it derives new rules by substituting bound variables of the rule with the source. All derived rules are then kept in the global variable

Parameters

rule_derivations.
fcmem	Forward chainer's working memory

Returns: A vector of chosen rules

Implements opencog::ForwardChainerCallBack.

Definition at line 59 of file DefaultForwardChainerCB.cc.

References opencog::FCMemory::get_cur_source(), opencog::FCMemory::get_rules(), rule_derivations, opencog::Handle::UNDEFINED, and unify().

Handle DefaultForwardChainerCB::gen_sub_varlist	(	const Handle &	parent,
		const Handle &	parent_varlist
	)

private

Definition at line 281 of file DefaultForwardChainerCB.cc.

References createVariableList, opencog::LinkCast(), opencog::FindAtoms::search_set(), python.undocumented.blocksworld::t, and opencog::FindAtoms::varset.

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bool DefaultForwardChainerCB::is_valid_implicant ( const Handle & h )

private

Checks whether an atom can be used to generate a bindLink or not.

Parameters

h	The atom handle to be validated.

Returns: A boolean result of the check.

Definition at line 372 of file DefaultForwardChainerCB.cc.

References opencog::Atom::getType(), opencog::FindAtoms::search_set(), and opencog::FindAtoms::varset.

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HandleSeq DefaultForwardChainerCB::subatom_unify	(	Handle	source,
		Rule *	rule
	)

private

Tries to unify sub atoms of implicant lists in

Parameters

rule	with
source.
source	An atom that might bind to variables in
rule.
rule	The rule object whose implicants are to be sub atom unified.

Returns: HandleSeq of derived rules from sub atoms unification.

Definition at line 166 of file DefaultForwardChainerCB.cc.

References opencog::get_all_unique_atoms(), opencog::Rule::get_implicant_seq(), python.bindlink::result, and unify().

HandleSeq DefaultForwardChainerCB::substitute_rule_part	(	AtomSpace &	as,
		Handle	hrule,
		const std::set< Handle > &	vars,
		const std::vector< std::map< Handle, Handle >> &	var_groundings
	)

Derives new rules from

Parameters

hrule	by replacing variables with their groundings.
as	An atomspace where the handles dwell.
hrule	A handle to BindLink instance
vars	The grounded var list in
hrule
var_groundings	The set of groundings to each var in
vars

Returns: A HandleSeq of all possible derived rules

Definition at line 320 of file DefaultForwardChainerCB.cc.

References opencog::BindLinkCast(), opencog::contains_atomtype(), createBindLink, gen_sub_varlist(), opencog::LinkCast(), and opencog::Substitutor::substitute().

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HandleSeq DefaultForwardChainerCB::unify	(	Handle	source,
		Handle	target,
		Rule *	rule
	)

private

Tries to unify the

Parameters

source	with target and derives new rules using
rule	as a template.
source	An atom that might bind to variables in
rule.
target	An atom to be unified with
source	rule The rule object whose implicants are to be unified.

Returns: HandleSeq of possible derivation of rules by substituting variables in implicants members of

Parameters

rule	with their mapped bindings.

Definition at line 102 of file DefaultForwardChainerCB.cc.

References _as, opencog::AtomSpace::add_atom(), createBindLink, gen_sub_varlist(), opencog::Rule::get_handle(), opencog::Rule::get_vardecl(), is_valid_implicant(), opencog::FindAtoms::search_set(), substitute_rule_part(), and opencog::FindAtoms::varset.

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Friends And Related Function Documentation

friend class ::DefaultForwardChainerCBUTest

friend

Definition at line 38 of file DefaultForwardChainerCB.h.

Member Data Documentation

AtomSpace& opencog::DefaultForwardChainerCB::_as

private

Definition at line 39 of file DefaultForwardChainerCB.h.

ForwardChainerPMCB opencog::DefaultForwardChainerCB::_fcpm

private

Definition at line 40 of file DefaultForwardChainerCB.h.

source_selection_mode opencog::DefaultForwardChainerCB::_ts_mode

private

Definition at line 41 of file DefaultForwardChainerCB.h.

std::map<Handle,std::vector<Handle> > opencog::DefaultForwardChainerCB::rule_derivations

Definition at line 60 of file DefaultForwardChainerCB.h.

The documentation for this class was generated from the following files:

opencog/rule-engine/forwardchainer/DefaultForwardChainerCB.h
opencog/rule-engine/forwardchainer/DefaultForwardChainerCB.cc

Public Member Functions

Public Attributes

Private Member Functions

Private Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

Member Data Documentation