Origin for each line in src/example01.red from check-in c1ddb4c814:

c1ddb4c814 2021-03-01    1: a:=sin (x);
c1ddb4c814 2021-03-01    2: b:=cos (x);
c1ddb4c814 2021-03-01    3: c:=a^2+b^2;
c1ddb4c814 2021-03-01    4: d:=a/b;
c1ddb4c814 2021-03-01    5: f:=tan (x)-d;
c1ddb4c814 2021-03-01    6: trigsimp c;
c1ddb4c814 2021-03-01    7: trigsimp f;
c1ddb4c814 2021-03-01    8: end;