丸め関数

x2+x2=x\left\lceil{\frac{x}{2}}\right\rceil + \left\lfloor\frac{x}{2}\right\rfloor = x
xyz=xyz\left\lfloor\frac{\left\lfloor\frac{x}{y}\right\rfloor}{z}\right\rfloor = \left\lfloor\frac{x}{yz}\right\rfloor
xyz=xyzまたはxyz\left\lfloor\frac{\left\lceil\frac{x}{y}\right\rceil}{z}\right\rfloor = \left\lfloor\frac{x}{yz}\right\rfloor または \left\lceil\frac{x}{yz}\right\rceil
nZ    n+x=n+xn \in \Z \implies n + \lfloor x \rfloor = \lfloor n + x \rfloor
min(x,y)=min(x,y)min(\lceil x \rceil, \lceil y \rceil) = \left\lceil min(x, y) \right\rceil