<html><body><div style="color:#000; background-color:#fff; font-family:verdana, helvetica, sans-serif;font-size:10pt"><div><span><br></span></div><div><span>Dear Developers and members, <br></span></div><div style="color: rgb(0, 0, 0); font-size: 13.3333px; font-family: verdana,helvetica,sans-serif; background-color: transparent; font-style: normal;"><br><span></span></div><div style="color: rgb(0, 0, 0); font-size: 13.3333px; font-family: verdana,helvetica,sans-serif; background-color: transparent; font-style: normal;"><span>I intend to solve system Ax=b with two preconditioners as follows: <br></span></div><div style="color: rgb(0, 0, 0); font-size: 13.3333px; font-family: verdana,helvetica,sans-serif; background-color: transparent; font-style: normal;"><br><span></span></div><div style="color: rgb(0, 0, 0); font-size: 13.3333px; font-family: verdana,helvetica,sans-serif; background-color: transparent; font-style: normal;"><span>P1^{-1} P2^{-1} A x =
P^{-1} P^{-1} b</span></div><div style="color: rgb(0, 0, 0); font-size: 13.3333px; font-family: verdana,helvetica,sans-serif; background-color: transparent; font-style: normal;"><br><span></span></div><div style="color: rgb(0, 0, 0); font-size: 13.3333px; font-family: verdana,helvetica,sans-serif; background-color: transparent; font-style: normal;"><span>where P1 and P2 are exclusively available as matrices. <br></span></div><div style="color: rgb(0, 0, 0); font-size: 13.3333px; font-family: verdana,helvetica,sans-serif; background-color: transparent; font-style: normal;"><span>This might be crazy to many. <br></span></div><div style="color: rgb(0, 0, 0); font-size: 13.3333px; font-family: verdana,helvetica,sans-serif; background-color: transparent; font-style: normal;"><br><span></span></div><div style="color: rgb(0, 0, 0); font-size: 13.3333px; font-family: verdana,helvetica,sans-serif; background-color: transparent; font-style: normal;"><span>I
thought to start with PCCOMPOSITE but i do not think it does exactly what I intend. </span></div><div style="color: rgb(0, 0, 0); font-size: 13.3333px; font-family: verdana,helvetica,sans-serif; background-color: transparent; font-style: normal;"><br><span></span></div><div style="color: rgb(0, 0, 0); font-size: 13.3333px; font-family: verdana,helvetica,sans-serif; background-color: transparent; font-style: normal;"><span>Any Idea would be appreciated. <br></span></div><div style="color: rgb(0, 0, 0); font-size: 13.3333px; font-family: verdana,helvetica,sans-serif; background-color: transparent; font-style: normal;"><br><span></span></div><div style="color: rgb(0, 0, 0); font-size: 13.3333px; font-family: verdana,helvetica,sans-serif; background-color: transparent; font-style: normal;"><span>A beginner!!! <br></span></div><div style="color: rgb(0, 0, 0); font-size: 13.3333px; font-family: verdana,helvetica,sans-serif; background-color: transparent;
font-style: normal;"><span>Abdul<br></span></div><div style="color: rgb(0, 0, 0); font-size: 13.3333px; font-family: verdana,helvetica,sans-serif; background-color: transparent; font-style: normal;"><span></span></div><div><span style="color:rgb(0, 0, 255);"><span style="font-family:verdana, helvetica, sans-serif;"><span style="font-family:lucida console, sans-serif;"></span></span></span><span style="color:rgb(0, 0, 255);"><span style="font-family:verdana, helvetica, sans-serif;"></span></span></div></div></body></html>