What it means
P ⇒ Q says that if P is true then Q is true. P ⇔ Q says each implies the other: they are true or false together.
Read aloud in real formulas
x = 2 ⇒ x² = 4
Aethel says
x equals 2 implies x squared equals 4
the converse fails: x could be −2
x² = 0 ⇔ x = 0
Aethel says
x squared equals 0 if and only if x equals 0
true both ways
Typing it
- LaTeX
- \Rightarrow, \Leftrightarrow, \implies, \iff
- Unicode
- U+21D2, U+21D4
Questions
How do you say ⇒ out loud?
It is usually read “implies”, and also “if and only if”.
What does ⇒ mean in maths?
P ⇒ Q says that if P is true then Q is true. P ⇔ Q says each implies the other: they are true or false together.
How do you type ⇒?
In LaTeX, write \Rightarrow, \Leftrightarrow, \implies, \iff. Its Unicode code point is U+21D2, U+21D4.