Mathematics, Math, Programming, Discrete Mathematics.
following do not check for the same things. {1, 3, 4}⊆{1, 2, 3, 4, 5} {{1, 3, 4}}⊆{1, 2, 3, 4, 5} {1, 3, 4}⊆{1, 2, 3, 4, 5} checks for if the elements 1, 3, 4 are members of the set {1, 2, 3, 4, 5} (which is true). HOWEVER {{1, 3, 4}}⊆{1, 2, 3, 4, 5} checks for if {1, 3, 4} is a member of the set