Origin for each line in src/example05.red from check-in c1ddb4c814:

c1ddb4c814 2021-03-01    1: (a+b)^2;
c1ddb4c814 2021-03-01    2: (a+b)^3;
c1ddb4c814 2021-03-01    3: (a+b)^4;
c1ddb4c814 2021-03-01    4: (a+b)^5;
c1ddb4c814 2021-03-01    5: (a+b)^6;
c1ddb4c814 2021-03-01    6: c:=(a+b)^6;
c1ddb4c814 2021-03-01    7: d:=(a+b)^3;
c1ddb4c814 2021-03-01    8: c/d;
c1ddb4c814 2021-03-01    9: a:=sin (x);
c1ddb4c814 2021-03-01   10: b:=cos (x);
c1ddb4c814 2021-03-01   11: c:=a^2+b^2;
c1ddb4c814 2021-03-01   12: d:=a/b;
c1ddb4c814 2021-03-01   13: f:=tan (x)-d;
c1ddb4c814 2021-03-01   14: % Trigo Rules;
c1ddb4c814 2021-03-01   15: trig1:={sin(~x)^2=>(1-cos(x)^2)};
c1ddb4c814 2021-03-01   16: let trig1;
c1ddb4c814 2021-03-01   17: trig2:={tan (~x)=>(sin (x)/cos (x))};
c1ddb4c814 2021-03-01   18: let trig2;
c1ddb4c814 2021-03-01   19: % now with rules;
c1ddb4c814 2021-03-01   20: c;
c1ddb4c814 2021-03-01   21: d;
c1ddb4c814 2021-03-01   22: f;
c1ddb4c814 2021-03-01   23: end;