es-bact{i:l}
es-bact(ds; da; a; es; n; e1; e2)
== Case TERMOF{decidableecl-es-act:ObjectId, 1:l, i:l}
== Case (ds == Case ,da == Case ,a == Case ,es == Case ,es-loc(es; e1)
== Case ,x.* == Case ,x,y. * == Case ,n == Case ,e1 == Case ,e2) of
== inl(x) true
== inr(x) false