Line loop vs Curve loop

I am a new user of gmsh, but I notices as issue with tutorial 1. When I ran the file t1.geo I got the following error: Error : 't1.geo', line 47 : Unknown variable 'Loop(.)'

I went to line 47 and changed the line to: "Line Loop(1) = {4,1,-2,3} ;"

Then I ran the file with this change and the code ran with one less error. The other error was: Error : 't1.geo', line 70 : syntax error (Curve)

I then changed this to: Physical Line(5) = {1, 2, 4} ;

And then the code ran without any error.