Mathematical notation

Examinations for CIE syllabuses may use relevant notation from the following list.

1 Set notation

∈ is an element of

∉ is not an element of

{x1, x2, …} the set with elements x1, x2, …

{x : …} the set of all x such that …

n(A) the number of elements in set A

∅ the empty set

the universal set

, the universal set (for 0607 IGCSE International Mathematics)

A′ the complement of the set A

ℕ the set of natural numbers, {1, 2, 3, …}

ℤ the set of integers, {0, ±1, ±2, ±3, …}

ℚ the set of rational numbers,

ℝ the set of real numbers

ℂ the set of complex numbers

(x, y) the ordered pair x, y

⊆ is a subset of

⊂ is a proper subset of

⋃ union

⋂ intersection

[a, b] the closed interval {x ∈ ℝ : a ⩽ x ⩽ b}

[a, b) the interval {x ∈ ℝ : a ⩽ x < b}

(a, b] the interval {x ∈ ℝ : a < x ⩽ b}

(a, b) the open interval {x ∈ ℝ : a < x < b}

(S, ∘) the group consisting of the set S with binary operation ∘

2 Miscellaneous symbols

= is equal to

≠ is not equal to

≡ is identical to or is congruent to

≈ is approximately equal to

~ is distributed as

≅ is isomorphic to

∝ is proportional to

< is less than

⩽ is less than or equal to

> is greater than

⩾ is greater than or equal to

∞ infinity

⇒ implies

⇐ is implied by

⇔ implies and is implied by (is equivalent to)

2020年10月11日 19:00