Does $\{\{a\}, \{b, \varnothing\}\}$ work as a definition of an ordered pair?
106068
Ordered pair - why so complicated?
134050
Question about set notation: what does $]a,b[$ mean?
130418
Is ${\{\emptyset,\{\emptyset\},\{\{\emptyset\}\},\{\{\{\emptyset\}\}\},...\}} $ a set?
62770
Does $a\mid bc$ imply $a\mid b$ or $a\mid c$?
83452
Prove that any conjugate of $a$ has the same order as $a$.
135250
Ordered Pair Formal Definition
131163
There is a well ordering of the class of all finite sequences of ordinals
41731
Question about the order of the product of two elements in an abelian group
149939
Number of ordered pairs $(a,b)$ such that $ab \le 3600$
93501
Order of precedence of set operators
11509
Relationship between $\operatorname{ord}(ab), \operatorname{ord}(a)$, and $\operatorname{ord}(b)$
74377
Is the natural order relation on an idempotent semiring total/linear?
61048
Is this a characterization of well-orders?
107540
how to prove that $abc$ and $cba$ do not necessarily have the same order?
80892
Does $\wp(A \cap B) = \wp(A) \cap \wp(B)$ hold? How to prove it?
74827
Integer ordered pair of $(x,y)$ in complex algebraic equation
82739
Why is $\alpha \rightarrow \forall x(\alpha)$ not generally correct in first-order logic?