
theorem Th30:
for X be non empty set, S be SigmaField of X, E be Element of S,
 f be PartFunc of X,REAL st E = {} holds f is E-measurable
proof
    let X be non empty set, S be SigmaField of X, E be Element of S,
    f be PartFunc of X,REAL;
    assume E = {}; then
    R_EAL f is E-measurable by Th29;
    hence f is E-measurable by MESFUNC6:def 1;
end;
