have n-to-1 mapping from location paths to a set of may-written shared descriptors.

have n-to-1 mapping from location paths to a set of may-written shared descriptors.
every call site propagates a set of may-written shared descriptors to the caller's arg location paths.
if an argument is bound to the callee's parameter leading to a write effect on shared locations, the corresponding location path that is started with the callee's param location will be bound to the caller's arg location path.
For example, suppose that caller has an arg with location path <A,B> and corresponding callee has param with location <L,C>. If the param leads to an write effect on shared location "F" through the location path <L,C,D,E>, the caller will have an write effect on F with the location path <A,B,C,D,E>.