1. For any received word w, compute wH.
2. If wH is the zero vector, assume no error was made.
3. If there is exactly one instance of a nonzero element s ∈ F and a row i of H such that wH is s times row i, assume the sent word was
w - (0,...,s,...,0), where s occurs in the i-th component. If there is more than one such instance, do not decode.
3'. When the code is binary, category 3 reduces to the following. If wH is the i-th row of H for exactly one i, assume
that an error was made in the i-th component of w. If wH is more than one row of H, do not decode.
4. If wH does not fit into either category 2 or category 3, we know that at least two errors occurred in transmission and we do not decode.