 It surprisingly turns out that one of such equivalent conditions applies the semidefinite programming (SDP) , which leads to a practical usefulness.
<meaning-changed>  It surprisingly turns out that one of such equivalent conditions applies the semidefinite programming (SDP) , which leads to a practical usefulness.
 It surprisingly turns out that one of such conditions leads to the existence of a positive definite solution to a semidefinite program (SDP) , which leads to a practical usefulness.