code: func le(arg1, arg2 interface{}) (bool, error) {
  	// <= is < or ==.
  	lessThan, err := lt(arg1, arg2)
  	if lessThan || err != nil {
  		return lessThan, err
  	}
  	return eq(arg1, arg2)
  }
docs: // le evaluates the comparison <= b.