Replace gensym with function of store.
Reachable state semantics.
Classical (v.c.-style) symbolic execution.
Revert ev-symbolic-unit; not needed for v.c.-style symbolic exec.
Use s-expressions in place of structs for better printing.
Eval for computing dead code.
Add multiplication to abs-delta.
Convert set to list in reachable semantics.
Call rec not ev from eval in pdcfa.
Example of PDCFA.