type opcode =
  | MATH of (int*int*int)
  | LOGIC of (int*int*int)
  | SCIENCE of int
  | PHYSICS of  int;;

let code instr =
  match instr with
    | MATH (d,a,b) -> 0x20 + d * 0x10 + a * 0x04 + b * 0x01
    | LOGIC (d,a,b) -> 0x40 + d * 0x08 + a * 0x04 + b * 0x01
    | SCIENCE hyp -> 0x00 + hyp
    | PHYSICS imm -> 0x60 + imm
;;
let string_of_prog prog name = "\n"
  ^"yang\n"
  ^"U+262F\n"
  ^"rm f\n/bin/umodem f PLOP\n"
  ^(List.fold_left (fun s op -> Printf.sprintf "%s%02X" s (code op)) "" prog)
  ^"PLOP\n./certify "^name^" f\n"
;;