method init : unit = (
Checkbutton.configure simplify ~command:(fun () -> (if simplifyString="" then simplifyString <- " -light " else simplifyString <- ""));
Checkbutton.configure untyped ~command:(fun () -> (if untypedString="" then untypedString <- " -notype " else untypedString <- ""));
Checkbutton.configure verbose ~command:(fun () -> (if verboseString="" then verboseString <- " -vv " else verboseString <- ""));
Listbox.insert lst ~index:`End ~texts:["Depth first"; "Breadth first"];
Listbox.selection_set lst ~first:(`Num 0) ~last:(`Num 0);
pack ~side:`Top [optionFrame];
pack ~side:`Top [optionLabel];
pack ~side:`Top [simplify];
pack ~side:`Top [untyped];
pack ~side:`Top [verbose];
pack ~side:`Top [search];
pack ~side:`Top [lst];)