# S.3. Persistence

This task set is centered around persistent data. There are two
database-focused tasks and two parsing-focused tasks.

 1. ‹a_lisp›     – a simple context-free parser
 2. ‹b_squelter› – storing the shelter objects with SQL
 3. ‹c_merkle›   – persistent trees
 4. ‹d_numeval›  – syntax + linear algebra