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seen Sep 16 at 8:52

Aug
6
revised Proper Set Theory Transformation
added 4 characters in body
Aug
6
answered Proper Set Theory Transformation
Aug
6
comment Set Theory Laws
We say that $A$ is a subset of $B$ if every element of $A$ is also an element of $B$. The proper subset is a different thing. If $A$ is a subset of $B$, but $A$ is not equal to $B$, then $A$ is a proper subset of $B$. To prove $(A \cup B \cup C) - (A \cup B) \subseteq (C - A) - B$, let $x \in (A \cup B \cup C) - (A \cup B)$ be arbitrary and then prove $x \in (C - A) - B$.
Aug
6
revised Set Theory Laws
added 2 characters in body
Aug
6
comment Set Theory Laws
I've only proved that $(C - A) - B \subseteq (A \cup B \cup C) - (A \cup B)$ and left the proof of $(A \cup B \cup C) - (A \cup B) \subseteq (C - A) - B$ to you. To prove $(C - A) - B = (A \cup B \cup C) - (A \cup B)$ you must prove both statements.
Aug
6
comment Set Theory Laws
What are $F$ and $G$? Elaborate on this.
Aug
6
answered Set Theory Laws
Aug
2
revised If $x^2\equiv 1 \pmod{n}$ and $x \not\equiv \pm 1 \pmod{n}$, then either $\gcd(x-1,n)$ or $\gcd(x+1,n)$ is a nontrivial factor of n
added 3 characters in body
Aug
2
revised Prove that $D_r \circ D_s = \{ (x,y) \in \mathbb{R}^2 \ | \ |x-y|<r+s \}$, where $D_a = \{ (x,y) \in \mathbb{R}^2\ | \ |x-y| < a \}$
edited tags
Jul
30
comment prove that : $\frac{a^2+b^2}{a+b} + \frac{b^2+c^2}{b+c}+ \frac{c^2+a^2}{c+a} \geq 3$
Check this answer.
Jul
30
answered Types versus kinds and sorts
Jul
28
awarded  Critic
Jul
28
answered Question about proving that a finite intersection of big unions is a big union of finite intersections
Jul
27
comment If the same message is sent to Alice and Bob who are using different public keys, how can somoene following the channel find $m$
Are you sure that the only given is $m < N_1$? Beware of the fact that if $m > N_2$, you won't get the exact $m$ back when you decrypt $c_2$.
Jul
27
revised If the same message is sent to Alice and Bob who are using different public keys, how can somoene following the channel find $m$
added 12 characters in body
Jul
27
answered How do I write a rigorous proof of the following problem: $(A \triangle B) \cup C \neq (A \cup C) \triangle (B \cup C)$
Jul
27
awarded  Yearling
Jul
27
revised Proving the properties of big union of unions for indexed sets
edited body
Jul
26
revised Proving the properties of big union of unions for indexed sets
deleted 23 characters in body
Jul
26
revised Proving the properties of big union of unions for indexed sets
edited body