15.1.13 Subspace generated by the rows of a matrix
The rowspace command finds
a basis for the row space of a matrix.
rowspace takes one mandatory argument and one
optional argument:
A, a matrix.
Optionally, var, a variable name.
rowspace(A ⟨,var ⟩) returns a
list of vectors which form a basis of the subspace generated by the
rows of A. With the optional argument var,
Xcas will store the dimension of the subspace generated by
the rows of A.