let get_preface () = "\\nonstopmode\n\\documentclass[12pt]{article}\n" ^
(if !modules_nonascii then get_encoding !modules_encoding else "") ^
(if !modules_ams then "\\usepackage{amsmath}\n\\usepackage{amsfonts}\n\\usepackage{amssymb}\n" else "") ^
let get_preface () = "\\nonstopmode\n\\documentclass[12pt]{article}\n" ^
(if !modules_nonascii then get_encoding !modules_encoding else "") ^
(if !modules_ams then "\\usepackage{amsmath}\n\\usepackage{amsfonts}\n\\usepackage{amssymb}\n" else "") ^