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definition:
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matchDTerms :: [Term] -> [DTerm] -> Maybe (Sub DTerm)
matchDTerms [] [] = Just []
matchDTerms [] (_:_) = Nothing
matchDTerms (_:_) [] = Nothing
matchDTerms (x:xs) (y:ys) = combineSubst (match x y) (matchDTerms xs ys)
where
combineSubst Nothing _ = Nothing
combineSubst (Just _ ) Nothing = Nothing
combineSubst (Just s1) (Just s2) = Just (s1++s2)
-- match a linear pattern against a term with disjoint variables:
match :: Term -> DTerm -> Maybe (Sub DTerm)
match (Var v) t = Just [(v,t)]
match (Func _ pf pargs) t = case t of
DBot -> Nothing
CutVar -> Just (map (\v->(v,CutVar)) (concatMap varsOf pargs))
DCons tf targs -> if pf==tf then matchDTerms pargs targs else Nothing
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demand:
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arguments 1 2
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deterministic:
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deterministic operation
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documentation:
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-- pairwise matching of a list of patterns against a list of terms
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failfree:
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<FAILING>
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indeterministic:
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referentially transparent operation
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infix:
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no fixity defined
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iotype:
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{({[]},{[]}) |-> {Just} || ({[]},{:}) |-> {Nothing} || ({:},{[]}) |-> {Nothing} || ({:},{:}) |-> {Just,Nothing}}
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name:
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matchDTerms
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precedence:
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no precedence defined
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result-values:
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{Just,Nothing}
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signature:
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[TRS.Term] -> [DTerm] -> Prelude.Maybe [(Prelude.Int, DTerm)]
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solution-complete:
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operation might suspend on free variables
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terminating:
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possibly non-terminating
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totally-defined:
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possibly non-reducible on same data term
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