|Class 11 Maths Sets||Sub sets|
A set A is said to be a subset of a set B if every element of A is also an element of B.
Consider set A = set of all students in your class, B = set of all students in your School.
We note that every element of A is also an element of B; we say that A is a subset of B.
A is subset of B is expressed in symbols as A ⊂ B. The symbol ⊂ stands for ‘is a subset of’ or ‘is contained in’.
It follows from the above definition that every set A is a subset of itself, i.e. A ⊂ A.
Since the empty set φ has no elements, we agree to say that φ is a subset of every set.