Krzysztof Maurin's notation

Analysis - Part I: Elements

Notation	Read as	Notes
$\wedge$	"and"
$\bigwedge_x$, $$\bigwedge_x$$	"for all $x$ there follows"	Equiv to $\forall x$, $x$ may be a statement (eg: $x:=y\in Y$)
$\vee$	"or"
$\bigvee_x$, $$\bigvee_x$$	"there exists an $x$ such that"	Equiv to $\exists x$, $x$ may be a statement (eg: $x:=y\in Y$)
$¬$	"Not"
$\implies$	"if, ..., then"	Meaning: if left side then right side, see Implies
$\iff$	"if and only if"	Implication in both directions, if left then right, if right then left
$:=$	"equal by definition"

Examples

Maurin gives some examples:

• Contrapositive: $(p\implies q)\iff(¬q\implies ¬p)$
• De Morgan's laws: $¬(p\wedge q)\iff(¬p\vee ¬q)$ and $¬(p\vee q)\iff(¬p\wedge ¬q)$