+ string (* problem label *)\r
+ * Num.i_var option (* div *)\r
+ * Num.i_n_var list (* conv *)\r
+ * Num.i_n_var list (* ps *)\r
+ * string list (* names of free variables *)\r
+val from_file : string ->\r
+ (string (* problem label *)\r
+ * Num.i_var option (* div *)\r
+ * Num.i_n_var list (* conv *)\r
+ * Num.i_n_var list (* ps *)\r
+ * string list (* names of free variables *)) list\r