let stringify_arith op suffix =
match op with
| Ast.Add -> "ADD_"^suffix
| Ast.Sub -> "SUB_"^suffix
| Ast.Prod -> "PROD_"^suffix
| Ast.Div -> "DIV_"^suffix
| Ast.Mod -> "MOD_"^suffix
| Ast.Neg -> raise(Failure "Unary operator")
| Ast.Pow -> "POW_"^suffix