What it means
A ⊆ B says every element of A is also in B. Some books use ⊂ for the same thing, others only for a proper subset, one that leaves something of B out.
Read aloud in real formulas
ℕ ⊆ ℤ
Aethel says
the natural numbers are a subset of the integers
every natural number is an integer
A ∩ B ⊆ A
Aethel says
A intersection B is a subset of A
what A and B share lies inside A
Typing it
- LaTeX
- \subseteq, \subset
- Unicode
- U+2286, U+2282
Questions
How do you say ⊆ out loud?
It is usually read “is a subset of”.
What does ⊆ mean in maths?
A ⊆ B says every element of A is also in B. Some books use ⊂ for the same thing, others only for a proper subset, one that leaves something of B out.
How do you type ⊆?
In LaTeX, write \subseteq, \subset. Its Unicode code point is U+2286, U+2282.