=ADD= =author= Abramsky; S. + Gabbay; Dov M. + Maibaum; T.S.E. =title= Handbook of Logic in Computer Science. Vol 3: Semantic Structures. =year= 1994 =publisher= Claredon Press =note= London =location= 2 =owner= 2 =source= 3 =reftype= 1