Suppose we encode the four vectors in by repeating the vector twice. Thus, we have

[0,0]→ [0,0,0,0]

[0,1]→ [0,1,0,1]

[1,0]→ [1,0,1,0]

[1,1]→ [1,1,1,1]

Show that this code is not error-correcting.