?url_ver=Z39.88-2004&rft_id=Technical+report+TR-02-14&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Feprints.imtlucca.it%2F181%2F&rft.title=Pi-Calculus+Early+Observational+Equivalence%3A+A+First+Order+Coalgebraic+Model&rft.creator=Buscemi%2C+Maria+Grazia&rft.creator=Montanari%2C+Ugo&rft.subject=QA75+Electronic+computers.+Computer+science&rft.description=In+this+paper%2C+we+propose+a+compositional+coalgebraic+semantics+of+the+pi-calculus+based+on+a+novel+approach+for+lifting+calculi+with+structural+axioms+to+coalgebraic+models.+We+equip+the+transition+system+of+the+calculus+with+permutations%2C+parallel+composition+and+restriction+operations%2C+thus+obtaining+a+bialgebra.+No+prefix+operation+is+introduced%2C+relying+instead+on+a+clause+format+defining+the+transitions+of+recursively+defined+processes.+The+unique+morphism+to+the+final+bialgebra+induces+a+bisimilarity+relation+which+coincides+with+observational+equivalence+and+which+is+a+congruence+with+respect+to+the+operations.+The+permutation+algebra+is+enriched+with+a+name+extrusion+operator+delta+a'+la+De+Brujin%2C+that+shifts+any+name+to+the+successor+and+generates+a+new+name+in+the+first+variable.+As+a+consequence%2C+in+the+axioms+and+in+the+SOS+rules+there+is+no+need+to+refer+to+the+support%2C+i.e.%2C+the+set+of+significant+names%2C+and%2C+thus%2C+the+model+turns+out+to+be+first+order.+&rft.publisher=Universit%C3%A0+di+Pisa%2C+Dipartimento+di+Informatica&rft.date=2002-08-01&rft.type=Working+Paper&rft.type=NonPeerReviewed&rft.identifier=++Buscemi%2C+Maria+Grazia+and+Montanari%2C+Ugo++Pi-Calculus+Early+Observational+Equivalence%3A+A+First+Order+Coalgebraic+Model.++Technical+Report+++Universit%C3%A0+di+Pisa%2C+Dipartimento+di+Informatica+++++++++&rft.relation=http%3A%2F%2Fcompass2.di.unipi.it%2FTR%2Ffiles%2FTR-02-14.ps.gz&rft.relation=Technical+report+TR-02-14