write down initial and boundary conditions separately

src/8_differential_equations_2.md

@@ -271,8 +271,9 @@ arise from the time derivative and likewise at least one from the spatial
 derivative. 
 
 For the Schrödinger equation, we could supply the initial conditions
-
-$$\psi(x,0)=\psi_0(x) \& \psi(0,t) = \psi(L, t) = 0 \text{for all $t$}.$$
+$$\psi(x,0)=\psi_0(x)$$
+together with the boundary conditions
+$$\psi(0,t) = \psi(L, t) = 0 \text{for all $t$}.$$
 
 This particular set of boundary conditions corresponds to a particle in a box,
 a situation which is used as the base model for many derivations in quantum