Final answer:
The student's question pertains to real-valued functions on a continuous interval, likely focusing on operations or properties of these functions.
Step-by-step explanation:
The subject of this question is Mathematics, specifically dealing with real-valued functions that are defined on an infinite interval, which is a topic typically addressed at the college level. While the student's question seems to be incomplete, it appears they are interested in properties or operations related to functions in a set V, which includes all real-valued functions defined on the interval (-∞, ∞). A complete answer would require the rest of the question, but generally, we could discuss how such functions might be added, multiplied, or composed, and describe their properties like continuity, differentiability, and integrability. Without the specific nature of the question involving f and g, two functions within V, we can only assume the question might relate to operations involving these functions or their properties.