// simple query
public boolean canQueryVar(RTVar v) {
if (v.isPrivate()) return false;
if (storeScheme == SELECTED) return canQueryVars[v.varID()];
return true;
}
public void addQueryVar(Expr expr) {
if (canQueryVars != null) {
RTVar v = (RTVar) expr;
canQueryVars[v.varID()] = true;
}
}