import java.util.*;

public class Term
{
    final char op;
    final Element arg1, arg2;

    Term(char op, Element arg1, Element arg2)
    {
        this.op = op;
        this.arg1 = arg1;
        this.arg2 = arg2;
    }

    Term(char variable)
    {
        this.op = variable;
        this.arg1 = null;
        this.arg2 = null;
    }

    Term(String s, ModLattice l) throws NumberFormatException
      /* This constructor is intended only for reading a lattice from a file. */
    {
        StringTokenizer st = new StringTokenizer(s);
        try {
            if (st.countTokens() == 3) {
                arg1 = l.elements[Integer.parseInt(st.nextToken())];
                op = st.nextToken().charAt(0);
                arg2 = l.elements[Integer.parseInt(st.nextToken())];
            }
            else {
                op = st.nextToken().charAt(0);
                arg1 = null;
                arg2 = null;
            }
        } catch (NullPointerException ex) {
            throw new NumberFormatException();
        }
    }
		  
    public boolean equals(Term x)
    {
        if (this.op == x.op)
            if ((this.arg1 == x.arg1 && this.arg2 == x.arg2) || (this.arg1 == x.arg2 && this.arg2 == x.arg1))
                return true;
            else
                return false;
         else
            return false;
    }

    public String toString()
    {
	if (op == 'v' || op == '^')
	    return (arg1.myNumber + " " + op + " " + arg2.myNumber);
	else
	    return (op + "");
    }

} //class Term