function B=f(A) /// \sleftarrow{\normalfont a typical {function} with one input and one output}
  B=string(sign(A));
  B=strsubst(strsubst(B,'1','+'),'-+','-');
endfunction 
f(rand(2,5,'n') )

function y=fact(x) /// \sleftarrow{\normalfont a recursive {function} can be defined: \verb+fact+ calls \verb+fact+}
  if x <= 1 then y=x; else y=x*fact(x-1);end 
endfunction

fact(4)