IsRowSpace( obj )
returns true if obj, which can be an object of arbitrary
type, is a row space and false otherwise.
gap> v:= GF(2) ^ 2;
RowSpace( GF(2), [ [ Z(2)^0, 0*Z(2) ], [ 0*Z(2), Z(2)^0 ] ] )
gap> IsRowSpace( v );
true
gap> IsRowSpace( v / [ v.generators[1] ] );
false
GAP 3.4.4