= Elimination multiplier
{title2=$l_{ik}=a_{ik}^{(k-1)}/a_{kk}^{(k-1)}$}
For $i>k$, an <elimination multiplier> is the <scalar> $l_{ik}=a_{ik}^{(k-1)}/a_{kk}^{(k-1)}$ used in the <elementary row operation> $R_i\leftarrow R_i-l_{ik}R_k$. This creates a zero below the <pivot element>. The remaining entries change by $a_{ij}\leftarrow a_{ij}-l_{ik}a_{kj}$ for $j>k$. Storing these <elimination multipliers> gives the subdiagonal entries of $L$ in <LU decomposition>; later row interchanges must also reorder the already stored coefficients.
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