Support a new feature 'set_used'
Support a new feature 'set_used'

AmeBel/opencog,andre-senna/opencog,AmeBel/opencog,andre-senna/opencog,AmeBel/opencog,AmeBel/opencog,andre-senna/opencog,AmeBel/opencog,AmeBel/opencog,AmeBel/opencog,andre-senna/opencog,andre-senna/opencog,andre-senna/opencog,andre-senna/opencog