Eigen stands for feature and Werk stands for value.
2. Stochastic processes can actually be used. However, the word "history" is more professional and a special word. Random has a wide meaning and is a general word.
Random is an English word, which comes from the Greek stochastikos.
I looked up Webster's Dictionary and found it.
In, random means involving random variables.
So here, randomness is more accurate than randomness.
3, r is the upper triangular matrix, also called the right triangular matrix.
4, p is the only invertible matrix.
I stands for identity matrix. So I can't be used.
If there is any relationship between invertibility and allowable matrix, there is a theorem: "If P is an allowable matrix, then P is also an invertible matrix, and its inverse matrix is P T."