Although the FORTRAN 77 standard prohibits aliasing arguments, the Sun Performance Library allows the programmer to alias two or more arguments as long as all aliased arguments have the same base type and one of the arguments being aliased is not the result array. A real variable and a complex variable have the same base type (real), while a real variable and a double precision variable have different base types. Aliasing arguments having different base types or aliasing any argument with the result array will produce undefined results at best. It is not even guaranteed that these undefined results will be the same from one run to the next.