1. Read through 6/3/2017

Software for instruction in logic (as used on http://softoption.us ).
This is the source code for the Trees Widget, which is some javascript
for displaying trees in propositional logic, predicate logic, first-order theories,
modal logic, and set theory. The Widget illustrates extension and closing of tree.
The code is written in Java and the project hosted and
developed in the Eclipse IDE, with GIT and the Google Web Toolkit (GWT) plug-in. The
GWT plug-in can run the project in Super Dev mode for development. Then it compiles the
Java to Javascript, which can be embedded in Web Pages (or ePubs, iBooks etc.).
Various 'switches' in those Web Pages allow the Proof Widget to be configured to run
the desired systems. Sample Web pages are included. For these, go to TreesJS/war/
and then use a web browser on Tutorial1.html etc.
