// equality for various classes
Constraint {
	public int hashCode() {{
		return toString().hashCode();
	}}

	public boolean equals(Object o) {{
		EqualVisitor ev = new EqualVisitor(o);
		toAll(ev);
		return ev.get_is_equal();
	}}
}

Weight {
	public boolean equals(Object o) {{
		return (o instanceof Weight) &&
			((Weight)o).get_weight() == weight;
	}}

	public int hashCode() {{
		return weight;
	}}
}

Relation {
	public boolean equals(Object o) {{
		return (o instanceof Relation) &&
		   ((Relation)o).get_relationNumber() == relationNumber;
	}}

	public int hashCode() {{
		return relationNumber;
	}}
}

Variable {
	public int hashCode() {{
		return variable;
	}}

	public boolean equals(Object o) {{
		return (o instanceof Variable) &&
			((Variable)o).get_variable() == variable;
	}}

	public String toString() {{
		return new Integer(variable).toString();
	}}
}

Literal {
	public boolean equals(Object o) {{
		return o instanceof Literal &&
		   o.toString().equals(toString());
	}}
}