if ((right instanceof VariableRef) || (right instanceof ParameterRef))
if (right instanceof VariableRefBase)
    public Expression getCompareValue() {	if (_value != null) return _value;	if (_exp == null) return null;	if (_exp instanceof EqualityExpr) {	    EqualityExpr exp = (EqualityExpr)_exp;	    Expression left = exp.getLeft();	    Expression right = exp.getRight();	    Type tleft = left.getType();	    Type tright = right.getType();	    	    if (left instanceof CastExpr) left = ((CastExpr)left).getExpr();	    if (right instanceof CastExpr) right = ((CastExpr)right).getExpr();	    	    try {		if ((tleft == Type.String) && (!(left instanceof Step)))		    _value = exp.getLeft();		if ((left instanceof VariableRef) ||		    (left instanceof ParameterRef))		    _value = new CastExpr(left, Type.String);	    }	    catch (TypeCheckError e) { }	    try {		if ((tright == Type.String) && (!(right instanceof Step)))		    _value = exp.getRight();		if ((right instanceof VariableRef) || 		    (right instanceof ParameterRef))		    _value = new CastExpr(right, Type.String);	    }	    catch (TypeCheckError e) { }	}	return _value;    }