
theorem Th41:
  Prod_Field(L-Field 1) = L-Field
& Borel_Sets c= Prod_Field(L-Field 1)
& for I being Subset of REAL st I is Interval holds I in Prod_Field(L-Field 1)
proof
    1 in Seg 1; then
A1: (L-Field 1).1 = L-Field by FUNCOP_1:7;
    hence Prod_Field(L-Field 1) = L-Field by MEASUR13:def 11;
    thus Borel_Sets c= Prod_Field(L-Field 1) by A1,MEASUR12:75,MEASUR13:def 11;
    hence thesis by MEASUR10:5;
end;
