Formal Verification of Hardware Components in Critical Systems

Listing 21

Formal definition of 4-bit binary parallel adder (with look-ahead carry).

(1)	Definition C2(D C B A d c b a e: bool) Aa(Aa)e.
(2)	Definition C3(D C B A d c b a e: bool)
(3)	Bb(Bb)(Aa) (Bb)(Aa)e.
(4)	Definition C4(D C B A d c b a e: bool)
(5)	Cc(Cc)(Bb) (Cc)(Bb)(Aa) (Cc)(Bb)(Aa)e.
(6)	Definition C5(D C B A d c b a e: bool)
(7)	Dd(Dd)(C4 D C B A d c b a e).
(8)	Definition S1(D C B A d c b a e: bool) (Aa)e.
(9)	Definition S2(D C B A d c b a e: bool)
(10)	(Bb) (C2 D C B A d c b a e).
(11)	Definition S3(D C B A d c b a e: bool)
(12)	(Cc) (C3 D C B A d c b a e).
(13)	Definition S4(D C B A d c b a e: bool)
(14)	(Dd) (C4 D C B A d c b a e).
(15)	Definition FA4bitLA (D C B A d c b a e: bool)
(16)	: (boolboolboolboolbool)
(17)	(C5 D C B A d c b a e,S4 D C B A d c b a e,S3 D C B A d c b a e,
(18)	S2 D C B A d c b a e, S1 D C B A d c b a e).