let S be non empty set ; for R being total Relation of S,S
for BASSIGN being non empty Subset of (ModelSP S)
for f, g being Assign of (BASSModel (R,BASSIGN))
for X being Subset of S holds (TransEU (f,g)) . X = (SIGMA g) \/ ((SIGMA f) /\ (Pred (X,R)))
let R be total Relation of S,S; for BASSIGN being non empty Subset of (ModelSP S)
for f, g being Assign of (BASSModel (R,BASSIGN))
for X being Subset of S holds (TransEU (f,g)) . X = (SIGMA g) \/ ((SIGMA f) /\ (Pred (X,R)))
let BASSIGN be non empty Subset of (ModelSP S); for f, g being Assign of (BASSModel (R,BASSIGN))
for X being Subset of S holds (TransEU (f,g)) . X = (SIGMA g) \/ ((SIGMA f) /\ (Pred (X,R)))
let f, g be Assign of (BASSModel (R,BASSIGN)); for X being Subset of S holds (TransEU (f,g)) . X = (SIGMA g) \/ ((SIGMA f) /\ (Pred (X,R)))
let X be Subset of S; (TransEU (f,g)) . X = (SIGMA g) \/ ((SIGMA f) /\ (Pred (X,R)))
set h = Tau (X,R,BASSIGN);
(TransEU (f,g)) . X =
SigFoaxTau (g,f,X,R,BASSIGN)
by Def73
.=
(SIGMA g) \/ (SIGMA (Fax (f,(Tau (X,R,BASSIGN)))))
by Th33
.=
(SIGMA g) \/ ((SIGMA f) /\ (SIGMA (EX (Tau (X,R,BASSIGN)))))
by Th33
.=
(SIGMA g) \/ ((SIGMA f) /\ (Pred ((SIGMA (Tau (X,R,BASSIGN))),R)))
by Th50
;
hence
(TransEU (f,g)) . X = (SIGMA g) \/ ((SIGMA f) /\ (Pred (X,R)))
by Th32; verum