1. GRAPHS, REACTIVE SYSTEMS AND MOBILE AMBIENTS Giacoma Valentina Monreale Supervisor: F. Gadducci

2. Graphical encoding for MAs ( n)(n[in m.0]|m[out m.0]) ambb inb out a p m ambient nameprocessactivation point ambbcap n[P]n[P]cap n.P Syntax: P:= 0, n[P], M.P, ( n)P, P 1 |P 2 M:= in n, out n, open n Sound and complete w.r.t. the structural congruence of MAs

3. Graph trasformation systems for MAs n[P]|open n.Q P|Q n[in m.P|Q]|m[R] m[n[P|Q]|R] m[n[out m.P|Q]|R] n[P|Q]|m[R] Reduction Semantics Graphs trasformation rules

4. LTS on graphs by the BC technique J F K G J n[in m.0] m[n[0]|X] -|m[X] We derive a LTS on graphs by applying the borrowed context technique, which is an instance of the theory of reactive systems H K

5. LTS for MAs The bisimilarity on the distilled LTS is too strict We propose notions of strong and weak barbed saturated semantics for LTS synthesized using the theory of reactive systems

6. (Weak) Barbed Semi-Saturated Bisimilarity Weak barbed semi-saturated bisimilarity WBSS is the largest weak barbed semi-saturated bisimulation. Definition. A symmetric relation R is a bisimulation if whenever P R Q then C[ ], if C[P] o then C[Q] o; if P P then C[Q] Q and P R Q. if P o then Q o C[-] Barbs are predicates over the states of a system: P o if P satisfies o Weak barbs : P o if P P and P o * if P o then Q o Barbed semi-saturated bisimilarity BSS is the largest barbed semi-saturated bisimulation. barbed semi-saturatedweak barbed semi-saturated (Weak) Barbed saturated bisimilarity for MAs coincides with (weak)strong reduction barbed congruence