Table 1. Mathematical symbol index.

Symbol	Description
$\mathrm{\Theta }$	Model parameters
X	Feature vector
Y	Target variable (e.g., salary)
$\epsilon$	Error term in regression
$\lambda$	Regularization coefficient
$\pi$	Jeffreys prior or GMM component weight
$\mu$	Mean parameter in Gaussian mixture models (GMM)
$\sigma$	Standard deviation or variance in GMM
$\beta$	Coefficients in regression models
L	Loss function
$f$	Mapping function or model output function
$\mathcal{D}$	Dataset
$\mathcal{L}$	Likelihood function or loss in context
$\mathcal{N}$	Gaussian distribution notation
$R^2$	Coefficient of determination
MAE	Mean absolute error