basis
definition
- a set of vectors in V form a basis for V if
- each vector in the set are linearly independent of each other
- they span the vector space (meaning each vector in the space can be expressed as linear combination of the basis vectors)

example
- given subspace S. basis of S is set B that has
- minimum cardinality
- span(B) = S
- cardinality of B is the dimension of S