Create SELF vertex to reduce the expansion of the atomspace
Decrease edges width
Update start-class on pom.xml
Add SELF to Globals
Use labels as semantic references rather than ids
Modify label IS_A to match new requirements
Solve bug with constants
Modify visualization
Add SELF AtomSpaceParam
Control the presence of SELF element to constraint
Add persistence logic
Add persistence.xa
Consider params in atom creation
Remove persistence.xa
Use two persistence files by atomType
Create EMPTY in Globals
Modify AtomSpace to load persistente data
Create readEdges method in AtomSpace
Load persistent data by default
Create edges.xa and vertices.xa