def int_to_bignumber(x): return model.w_bignumber(rbigint.rbigint.fromint(x))
def mod_bignumber(x, y): return model.w_bignumber(x.mod(y))
def div_bignumber(x, y): return model.w_bignumber(x.div(y))
def mult_bignumber(x, y): return model.w_bignumber(x.mul(y))
def plus_bignumber(x, y): return model.w_bignumber(x.add(y))
def minus_bignumber(x, y): return model.w_bignumber(x.sub(y))