code: func DecimalMod(from1, from2, to *MyDecimal) error {
  	to.resultFrac = myMaxInt8(from1.resultFrac, from2.resultFrac)
  	return doDivMod(from1, from2, nil, to, 0)
  }
docs: /*
  DecimalMod does modulus of two decimals.
  
        from1   - dividend
        from2   - divisor
        to      - modulus
  
    RETURN VALUE
      E_DEC_OK/E_DEC_TRUNCATED/E_DEC_OVERFLOW/E_DEC_DIV_ZERO;
  
    NOTES
      see do_div_mod()
  
    DESCRIPTION
      the modulus R in    R = M mod N
  
     is defined as
  
       0 <= |R| < |M|
       sign R == sign M
       R = M - k*N, where k is integer
  
     thus, there's no requirement for M or N to be integers
  */