uni/inf1080/hw9.mdn

# Innlevering 9

## 15.10

A) $\forall$x$\forall$yRxy
	* Rxy: (x > y) \lor (x <= y)

B) $\exists$x$\forall$yRxy
	* Rxy: x <= y

C) $\forall$x$\exists$yRxy \land $\lnot$$\exists$xRxx
	* Rxy: (x > y) \lor (x < y)

D) $\exists$x$\exists$y(Rxy \land $\lnot$Ryx) \land $\forall$xRxx
	* Rxy: (x > y) \lor ($\lnot$(x > y) \lor $\lnot$(x < y))

## 16.4

A) $\exists$x(Liten(x) \land Trekant(x))
	* Usann

B) $\exists$x(Liten(x) \land Firkant(x))
	* Sann

C) $\forall$x(Liten(x) \to Firkant(x))
	* Usann

D) $\forall$x(Sirkel(x) \to Liten(x))
	* Sann

E) $\forall$x(Trukant(x) \to Stor(x))
	* Sann

F) $\forall$x$\lnot\exists$y(Under(x, y))
	* Sann

## 16.7

* $\exists$x$\exists$yRxy er en logisk konsekvens av $\forall$x$\forall$yRxy