Does a law for A in boolean algebra hold true for not A as well?
117171
De-Morgan's theorem for 3 variables?
40655
Propositional Logic - Can you Derive $C \to A$ from $A$ alone, given the introduction rule?
47232
Prove $\forall a,b,c \in \mathbb Z$, if $ab+ac\equiv 3\pmod 6$ then $b \not\equiv c \pmod 6$ by contraposition
71717
Is this always true: $P(A|B) = 1-P(A^c|B)$?
113735
Do we need to prove that if x∉A in proposition "if A⊆B then A⋃B=B"?
111800
If $a|c$ and $b|d$, is it true that $ab|cd$?
111763
True or False $A - C = B - C $ if and only if $A \cup C = B \cup C$
125348
Does $\det(A + B) = \det(A) + \det(B)$ hold?
32929
Questions about proving $\lnot \lnot a = a$
131761
Boolean expressions in Java
105233
Is there a counterexample for the claim: if $A \oplus B\cong A\oplus C$ then $B\cong C$?
94771
Not every boolean function is constructed from $\wedge$ (and) and $\vee$ (or)
17677
Prove or show a counter example for: $\forall a, b, c \in \mathbb Z$, if $ab\mid c$ then $a\mid c$ and $b\mid c$
146891
Why is $\{\emptyset\} \not = \emptyset$?
148824
Is associative binary operator closed on this subset?
65379
Deriving $\neg R$ from $\{R↔(R∨(P∧¬P)), R↔¬P, ¬P→(P↔(Q→Q)), P→Q\}$
89190
Why is it true that $|AB:A|=|B:A\cap B|$ even if $A$ is not normal in $AB$? (Second Isomorphism Theorem)