Why does the nullspace of A is in Rn instead of Rm when the special solution vectors have m components####[['nullspace of A', 'Mathematical_Related_Concept', 'NEU'], ['Rn', 'Mathematical_Related_Concept', 'NEU'], ['Rm', 'Mathematical_Related_Concept', 'NEU'], ['special solution vectors', 'Mathematical_Related_Concept', 'NEU']]