GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
% Add comments after a % character at the beginning of a line. % A comment can have several lines. % Here is a multi-line input block: g := MathieuGroup(11);; cl := ConjugacyClasses(g); % Calling a help page ?MathieuGroup % The next line contains a comment in the GAP session: a := 12;; b := 13;; # assign two numbers % a*b; %