10.downto(1) {|y| puts y}
(1) (-1e10) (0xabcdef) 'y'
[x] x->y x.y
!x ~x x++ x-- x*y x&y
x*y x/y x%y
x+y x-y
x<<y x>>y
x<y x<=y x>y x>=y
x==y x!=y
x&y
x^y
x|y
x&&y
x||y
x?y:z
x=y x+=y x-=y x*=y x/=y x%=y x<<=y x>>=y x&=y x^=y x|=y
x,y