% 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;
%
