Portability | H98 |
---|---|
Stability | experimental |
Maintainer | Douglas Burke |
This module defines a framework for constructing proofs over some expression form. It is intended to be used with RDF graphs, but the structures aim to be quite generic with respect to the expression forms allowed.
It does not define any proof-finding strategy.
- data Proof ex = Proof {
- proofContext :: [Ruleset ex]
- proofInput :: Formula ex
- proofResult :: Formula ex
- proofChain :: [Step ex]
- data Step ex = Step {}
- checkProof :: Expression ex => Proof ex -> Bool
- explainProof :: Expression ex => Proof ex -> Maybe String
- checkStep :: Expression ex => [Rule ex] -> [ex] -> Step ex -> Bool
- showProof :: ShowM ex => String -> Proof ex -> String
- showsProof :: ShowM ex => String -> Proof ex -> ShowS
- showsFormula :: ShowM ex => String -> Formula ex -> ShowS
Documentation
Proof is a structure that presents a chain of rule applications that yield a result expression from a given expression
Proof | |
|
Step in proof chain
The display name for a proof step comes from the display name of its consequence formula.
checkProof :: Expression ex => Proof ex -> BoolSource
Check consistency of given proof. The supplied rules and axioms are assumed to be correct.
explainProof :: Expression ex => Proof ex -> Maybe StringSource
Check proof, and return identification of failing step.
showProof :: ShowM ex => String -> Proof ex -> StringSource
Returns a simple string representation of a proof.
showsProof :: ShowM ex => String -> Proof ex -> ShowSSource
Create a displayable form of a proof, returned as a ShowS
value.
This function is intended to allow the calling function some control of multiline displays by providing:
- the first line of the proof is not preceded by any text, so it may be appended to some preceding text on the same line,
- the supplied newline string is used to separate lines of the formatted text, and may include any desired indentation, and
- no newline is output following the final line of text.