Variable.java

// Kimberley Ni and Eylul Oktay

public class Variable implements Expression {
	private String name;
	private String nameAugment;
	private int version;

	public Variable(String name) {
		this.name = name;
		this.nameAugment = "";
		this.version = 0;
	}

	public void augmentName() {
		nameAugment = Integer.toString(++version);
	}

	@Override
	public String toString() {
		return name + nameAugment;
	}

	@Override
	public Boolean isSimple() {
		return true;
	}

	@Override
	public Expression returnReplaced(String x, Expression replacement) {
		if (x.equals(this.toString())) {
			return replacement;
		}
		return copy();
	}

	@Override
	public Expression copy() {
		return new Variable(name);
	}

	@Override
	public Boolean equals(Expression other) {
		if (other instanceof Variable) {
			Variable comparative = (Variable) other;
			if (comparative.toString().equals(this.toString()))
				return true;
		}
		return false;
	}

	@Override
	public Boolean contains(Variable x) {
		if (x.equals(this)) {
			return true;
		}
		return false;
	}
}