(//) comments
A sequence of two consecutive slashes // out of a string definition marks the beginning of a comment. The slashes as well as all the following characters up to the end of the lines are not interpreted.
Inside a function, the first comment lines, up to the first instruction or an empty line may be used to provide the default contents for the function help.
g=9.81// the gravity
text='a//b'
function y=myfunction(x)
// myfunction computes y=x^2+1
// x shoudd be a vector or matrix
y=x^2+1
endfunction
`help`_ myfunction