semiring::Why Class Reference

Why-provenance semiring. More...

#include "Why.h"

Inheritance diagram for semiring::Why:

Collaboration diagram for semiring::Why:

Public Member Functions
value_type	zero () const override
	Return the additive identity \(\mathbb{0}\).
value_type	one () const override
	Return the multiplicative identity \(\mathbb{1}\).
value_type	plus (const std::vector< value_type > &vec) const override
	Apply the additive operation to a list of values.
value_type	times (const std::vector< value_type > &vec) const override
	Apply the multiplicative operation to a list of values.
virtual value_type	monus (value_type x, value_type y) const override
	Apply the monus (m-semiring difference) operation.
value_type	delta (value_type x) const override
	Apply the \(\delta\) operator.
virtual bool	compatibleWithBooleanRewrite () const override
	No semiring homomorphism BoolFunc(Y) →+* Why exists, so the safe-query Boolean rewrite is unsound under why-provenance.
value_type	parse_leaf (const char *v) const
	Parse a leaf value into a why-provenance set-of-sets.
std::string	to_text (const value_type &prov) const
Public Member Functions inherited from semiring::Semiring< why_provenance_t >
virtual value_type	cmp (value_type s1, ComparisonOperator op, value_type s2) const
	Evaluate a comparison gate.
virtual value_type	semimod (value_type x, value_type s) const
	Apply a semimodule scalar multiplication.
virtual value_type	agg (AggregationOperator op, const std::vector< value_type > &s)
	Evaluate an aggregation gate.
virtual value_type	value (const std::string &s) const
	Interpret a literal string as a semiring value.
virtual	~Semiring ()=default
virtual bool	absorptive () const
	Return true if this semiring is absorptive ( \(\mathbb{1} \oplus a = \mathbb{1}\) for all \(a\)).

Additional Inherited Members
Public Types inherited from semiring::Semiring< why_provenance_t >
typedef why_provenance_t	value_type
	The carrier type of this semiring.

Detailed Description

Why-provenance semiring.

Each gate evaluates to a why_provenance_t (set of witness sets).

Definition at line 56 of file Why.h.

Member Function Documentation

compatibleWithBooleanRewrite()

virtual bool semiring::Why::compatibleWithBooleanRewrite ( ) const

inlineoverridevirtual

No semiring homomorphism BoolFunc(Y) →+* Why exists, so the safe-query Boolean rewrite is unsound under why-provenance.

(Why tracks set-of-witness-sets per derivation; the read-once rewrite collapses witnesses in general.) Inherits the false default from Semiring; this override exists for documentation.

Lean: Provenance.Semirings.Why.no_hom_from_BoolFunc (provenance-lean/Provenance/Semirings/Why.lean).

Reimplemented from semiring::Semiring< why_provenance_t >.

Definition at line 119 of file Why.h.

delta()

value_type semiring::Why::delta ( value_type x ) const

inlineoverridevirtual

Apply the \(\delta\) operator.

Parameters

x	Input value.

Returns

\(\delta(x)\).

Implements semiring::Semiring< why_provenance_t >.

Definition at line 104 of file Why.h.

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monus()

virtual value_type semiring::Why::monus ( value_type x, value_type y ) const

inlineoverridevirtual

Apply the monus (m-semiring difference) operation.

Parameters

x	Minuend.
y	Subtrahend.

Returns

\(x \ominus y\).

Implements semiring::Semiring< why_provenance_t >.

Definition at line 97 of file Why.h.

one()

value_type semiring::Why::one ( ) const

inlineoverridevirtual

Return the multiplicative identity \(\mathbb{1}\).

Returns

The one element of the semiring.

Implements semiring::Semiring< why_provenance_t >.

Definition at line 64 of file Why.h.

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parse_leaf()

value_type semiring::Why::parse_leaf ( const char * v ) const

inline

Parse a leaf value into a why-provenance set-of-sets.

Accepted input formats (round-trip with to_text):

• Bare label (no leading '{'): "Alice" → {{Alice}}
• Empty set-of-sets: "{}" → zero
• Full form: "{{a},{b,c}}" → {{a},{b,c}} (in particular "{{}}" parses as one)

Labels may contain any character except ',', '{', '}'.

Definition at line 134 of file Why.h.

plus()

value_type semiring::Why::plus ( const std::vector< value_type > & v ) const

inlineoverridevirtual

Apply the additive operation to a list of values.

Parameters

v	Ordered list of operands (empty list should return zero()).

Returns

\(v_0 \oplus v_1 \oplus \cdots\).

Implements semiring::Semiring< why_provenance_t >.

Definition at line 69 of file Why.h.

times()

value_type semiring::Why::times ( const std::vector< value_type > & v ) const

inlineoverridevirtual

Apply the multiplicative operation to a list of values.

Parameters

v	Ordered list of operands (empty list should return one()).

Returns

\(v_0 \otimes v_1 \otimes \cdots\).

Implements semiring::Semiring< why_provenance_t >.

Definition at line 78 of file Why.h.

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to_text()

std::string semiring::Why::to_text ( const value_type & prov ) const

inline

Definition at line 186 of file Why.h.

zero()

value_type semiring::Why::zero ( ) const

inlineoverridevirtual

Return the additive identity \(\mathbb{0}\).

Returns

The zero element of the semiring.

Implements semiring::Semiring< why_provenance_t >.

Definition at line 59 of file Why.h.

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

• /home/pierre/git/software/provsql/src/semiring/Why.h