*ML笔记--1.2 formalize the learning probelm

Basic notations

input:     x∈χ  (customer application)

output:   y∈y  (good/bad after approving credit card)

target function (unknown pattern to be learned) : f: x→y  (ideal credit approval formula)

data (training examples): D = {(x₁,y₁),(x₂,y₂),...,(x_n,y_n)}   (historical records in bank)

hypothesis (skill with hopefully good performance)    g: x→y (learned formula to be used)