Discrete Structures

Translate each of these nested quantifications into an English statement that expresses a mathematical fact. The domain in each case consists of all real numbers.

a) xy(x+y=y)

b) xy(((x0)(y<0))(xy>0))

c) xy(((x0)(y0))(xy>0))

d) xy((x = 0)(y = 0) (xy = 0))