es:ES, e1, e2:E, P:({e:E| loc(e) = loc(e1)  Id & first(e) }Prop).
loc(e2) = loc(e1)  Id  e@loc(e1). first(e)  Dec(P(e))  Dec(e(e1,e2].P(e)) 

latex

Definitions	x:A. B(x), P & Q, Prop, P  Q, x(s), e(e1,e2].P(e), t  T, x. t(x), e@i. P(e), A & B, A, Dec(P), x:A. B(x), P  Q, {T}, P  Q, (e <loc e'), False, ee'.P(e)
Lemmas	alle-at wf, not wf, assert wf, es-first wf, decidable wf, Id wf, es-loc wf, es-E wf, event system wf, decidable existse-le, es-locl wf, es-locl-iff, decidable cand, decidable es-locl, es-le wf, es-le-loc, es-loc-pred