over : 2 pick
2dup : over over

arithmetic : \
  " A=" ,t over , sp " B=" ,t dup , nl \
  " A+B=" ,t 2dup + , nl \
  " A-B=" ,t 2dup - , nl \
  " A*B=" ,t 2dup * , nl \
  " A/B=" ,t 2dup / , nl \
  " A%B=" ,t      % , nl