replaced \sim with \precsim to make it clearer that we mean simulation
rather than bisimulation (that there is a direction).
progress and preservation theorem reviewed and fixed
fixed compile error, minor layout problems in progress/preservation proof
removed unnecessary / unwritten proofs for remap, all typing proofs
reviewed and fixed. principal typing proof still broken.
resync source, building TODO of all remaining tasks to wrap this
work up
removing redundant file
strong update removed, top type introduced and join rewritten,
more tests required
bool and top types now parsed for explicit type annotations
small additional check on precedence of parsing seq vs let binding
fixed parsing of object types (brought in line with paper),
object values and types now checked for duplicate states, methods and
missing states
fixing join/meet with respect to top type
using newly learned trick to exclude counter from default equals
and hashcode implementation for multi equation