A Distribution Law for CCS and a New Congruence Result for the pi-calculus

We give an axiomatisation of strong bisimilarity on a small fragment of CCSthat does not feature the sum operator. This axiomatisation is then used toderive congruence of strong bisimilarity in the finite pi-calculus in absenceof sum. To our knowledge, this is the only nontrivial subcalculus of thepi-calculus that includes the full output prefix and for which strongbisimilarity is a congruence.Comment: 20 page