Let the functions $\blacktriangle $ and $\blacktriangledown$ be defined as $X\blacktriangle Y = \sim (X\wedge Y) $ and $X\blacktriangledown Y = \sim (X\vee Y)$
Represent the following function ( only use $\blacktriangle $ and $\blacktriangledown$)
$X \rightarrow Y$
Correct answer:
$X \rightarrow Y \Leftrightarrow X \blacktriangle (Y\blacktriangle Y) \Leftrightarrow ((X \blacktriangledown X) \blacktriangledown Y) \blacktriangledown(X \blacktriangledown X) \blacktriangledown Y)$
I don’t get it? What’s going on here?