- If a row does not consist entirely of zeros, then the first non-zero number in the row is a 1. leading 1.
- If there are any rows that consist entirely of zeros, then they are grouped together at the bottom of the matrix.
- In any two successive rows that do not consist entirely of zeros, the leading 1 in the lower row occurs farther to the right than the leading 1 in the higher row.
- Each column that contains a leading 1 has zeros everywhere else in that column.
A matrix that has the first three properties is said to be in row echelon form.
Rank