dap4/d4core/src/main/java/dap4/core/ce/CEConstraint.java
protected int findVariableIndex(DapVariable var)
    {
        for(int i = 0; i < variables.size(); i++) {
            if(variables.get(i) == var)
                return i;
        }
        return -1;
    }
protected int findVariableIndex(DapVariable var)
    {
        for(int i = 0; i < variables.size(); i++) {
            if(variables.get(i) == var)
                return i;
        }
        return -1;
    }
/* Search the set of variables