Final answer:
The subject of this question is Mathematics, specifically the concept of subsets. Phi is a subset of {1,2,3,4,5,6}.
Step-by-step explanation:
The subject of this question is Mathematics, specifically the concept of subsets. A subset is a collection of elements that are taken from a larger set. In this case, the larger set is {1,2,3,4,5,6} and 'Phi' is a subset of this set.
A set is a well-defined collection of distinct objects. The set {1,2,3,4,5,6} contains the numbers 1, 2, 3, 4, 5, and 6. Phi, denoted as Φ, can be any subset of these numbers.
For example, if Φ is the set {1,2,4}, then it is a subset of {1,2,3,4,5,6}.