Of course, $\always\prop$ is persistent for any $\prop$.
Furthermore, by the proof rules given above, $t = t'$ as well as $\ownGGhost{\munit(\melt)}$ and $\knowInv\iname\prop$ are persistent.
Furthermore, by the proof rules given above, $t = t'$ as well as $\ownGGhost{\mcore\melt}$ and $\knowInv\iname\prop$ are persistent.
Persistence is preserved by conjunction, disjunction, separating conjunction as well as universal and existential quantification.
In our proofs, we will implicitly add and remove $\always$ from persistent assertions as necessary, and generally treat them like normal, non-linear assumptions.