ND1750ND1750Proof system for propositional logic with connectives ,,,, false, true:

A B , A

.·. B

A B , B

.·. A

A , B

.·. A B

A B

.·. A

A B

.·. B

A

.·. A B

B

.·. A B

A B , A

.·. B

A B , B

.·. A

MP MT

Conj

Simp

Add

DS

A B , A C, B D

.·. C D

A A

.·. AContr (Contraction)

CD

.·. A AXM (Excluded middle)

.·. true

TI (Truth Introduction)

false

.·. AFE (Falsehood Elimination)

… plus special rule CP.(and HS and DD if you like)

Not in book