440 Did the Gospel writers use lost documents known as Q,M & L as their sources for the Gospels?

Did Mark write his Gospel for Peter before Matthew wrote his Gospel?
Did Matthew use Mark and 2 lost sources known as Q & M as his source materials for writing his Gospel account?
Did Luke then use Mark, Mathew, and a lost source known as L as the sources for his Gospel?
As convoluted as these hypotheses all sound, this is what is taught in most seminaries. In this stream, I test the hypotheses against the evidence and see how they stand up.