% - indicates comments in the source.
{ \def<definition>#1 }
% indicates comments in the source code. Not rendered in final output.
% Note: (x+1)^2 is NOT x^2 + 1 will not get printed
% Note: (x+1)^2 is NOT x^2 + 1 (x+1)^2 % original expression = (x+1)(x+1) % definition of exponent = x^2 + 2x + 1 % FOIL, combine like terms