Hello, I don't succeed finding what is wrong. The file is a worksheet in 2D math

I always get 'error, invalid loop'. The text in bold is my simple program, the other text was added while copy-paste

restart
som := 0
                         
for i from 1 by 1 to 10 do
Error, invalid loop
 Typesetting:-mambiguous(Typesetting:-mambiguous(

   for i from 1 to 10 do, Typesetting:-merror("invalid loop")))

som := som + i;
                         

od;
Error, unable to parse
      Typesetting:-mambiguous(Typesetting:-mambiguous(od,

        Typesetting:-merror("unable to parse")))

NULL;

NULL;