I want to show that $L_1 = \{\langle M\rangle \mid \emptyset \subseteq L(M)\}$ is decidable/undecidable - without rice theorem (just for the case that I can apply it).
Every language contain the $\emptyset$ as a subset. So my guess is that the language is decidable.
Therefore, let us assume that $L_1$ is decidable. Lets say that $N$ is the TM which decides $L_1$.
N = "with input $<M>$:"
- ...
How can I prove that $N$ is a decider for $L_1$?