The wave function for spins without position can be seen as a complex wave vector $\psi=(\psi_1,\psi_2,\ldots)$ and the probability to measure a state $\psi^{(A)}$ in another state $\psi^{(B)}$ is $$ P=|\langle\psi^{(A)}|\psi^{(B)}\rangle|^2 $$ The relativistic Dirac wave equation is $$ i\hbar \gamma^\mu\partial_\mu\Psi-mc\Psi=0 $$ where gamma matrices appear.
What is the relation between both concepts $\psi$ and $\Psi$? Can I use Born's rule on the relativistic wave function somehow?
