code: def to_string(mnemonic):
          
          strings = {
              # Arithmetic Instructions
              ReilMnemonic.ADD: "add",
              ReilMnemonic.SUB: "sub",
              ReilMnemonic.MUL: "mul",
              ReilMnemonic.DIV: "div",
              ReilMnemonic.MOD: "mod",
              ReilMnemonic.BSH: "bsh",
  
              # Bitwise Instructions
              ReilMnemonic.AND: "and",
              ReilMnemonic.OR:  "or",
              ReilMnemonic.XOR: "xor",
  
              # Data Transfer Instructions
              ReilMnemonic.LDM: "ldm",
              ReilMnemonic.STM: "stm",
              ReilMnemonic.STR: "str",
  
              # Conditional Instructions
              ReilMnemonic.BISZ: "bisz",
              ReilMnemonic.JCC:  "jcc",
  
              # Other Instructions
              ReilMnemonic.UNKN:  "unkn",
              ReilMnemonic.UNDEF: "undef",
              ReilMnemonic.NOP:   "nop",
  
              # Extensions
              ReilMnemonic.SEXT: "sext",
              ReilMnemonic.SDIV: "sdiv",
              ReilMnemonic.SMOD: "smod",
              ReilMnemonic.SMUL: "smul",
          }
  
          return strings[mnemonic]
docs: Return the string representation of the given mnemonic.