theorem Th74: :: REWRITE3:74

for x1, x2, y1, y2 being object
for E being non empty set
for F being Subset of (E ^omega)
for TS being non empty transition-system over F st x1,x2 ==>. y1,y2,TS holds
==>.-relation TS reduces [x1,x2],[y1,y2]