tamarin-prover-term-1.2.2: Term manipulation library for the tamarin prover.

Copyright(c) 2010-2012 Benedikt Schmidt
LicenseGPL v3 (see LICENSE)
MaintainerBenedikt Schmidt <beschmi@gmail.com>
Safe HaskellNone
LanguageHaskell98

Term.Subsumption

Contents

Description

Subsumption of terms and substitutions.

Synopsis

Documentation

compareTermSubs :: LNTerm -> LNTerm -> WithMaude (Maybe Ordering) #

Compare terms t1 and t2 with respect to the subsumption order modulo AC.

eqTermSubs :: LNTerm -> LNTerm -> WithMaude Bool #

Returns True if s1 and s2 are equal with respect to the subsumption order modulo AC.

factorSubstVia :: [LVar] -> LNSubst -> LNSubst -> WithMaude [LNSubst] #

factorSubstOn s1 s2 vs factors the free substitution s1 through free substitution s2 on vs, i.e., find a complete set of free substitutions s such that for all vars x elem vs: > applyVTerm s1 x =AC= applyVTerm s (applyVTerm s2 x).

Canonical representations for substitutions

canonizeSubst :: LNSubstVFresh -> LNSubstVFresh #

Returns a substitution that is equivalent modulo renaming to the given substitution.

for testing only

varOccurences :: HasFrees a => a -> [(LVar, Set Occurence)] #

Returns the variables occuring in t together with the contexts they appear in. Note that certain contexts (and variables only occuring in such contexts) are ignored by this function. The function is used to "guess" renamings of variables, i.e., if t is a renaming of s, then variables that occur in equal contexts in t and s are probably renamings of each other.